No, really, I just care about hygiene

Two big things I love:

• Three action system: every "activity" (strike, stride, cast a spell, etc) has an action cost. On a standard turn, your character gets 3 actions to spend on those various activities. This obviates the need for DnD's rules about spending a whole turn running since you can just spend multiple actions striding.
• Keyword system: PF2e leans more onto standardized keywords and uses them appropriately. Everything (all actions, weapons, items, even statuses) has a set of traits that (usually) briefly explains how the thing acts. It allows for standardized templates for interactions between different elements of the game. This takes a HUGE burden off the GM during game play, esp for modules that weren't written to think about each other. All the examples I can think of would take several pages to explain, but you can look up some things on Easy Tools and see their traits.

Bonus thing I love: all the rules are openly published, leading to TONS of extra tools that just make the game easier to run. (That said you should buy a set of books to help the publishers after you've been converted).

Not OP but the top 3 for me are

1. Martial - Caster balance
2. 3 action economy
3. A much better framework for GMs

3 action economy for me, I also like that the rules are much clearer and more balanced to more play styles.

i do have a group that we've been playing since covid lockdowns via roll20 and later foundry and Unfortunately i don't have blocks of time for more games (i wish i did!). My comment was mostly just aimed at that all local my friends play d&d and don't want to switch.

But if you're looking to play pathfinder2e online there are communities like the pathfinder2e subreddit which has an active discord community. Foundryvtt has a very active pathfinder2e community (but LFG is done through main foundry discord).

And if you're not opposed to Organized Play (paizos version of adventurers league) then they have in store and online one-shots you can join. It's actually how i met my group but we branched off and did our own thing.

I'm looking to DM kingmaker on pf2e! Let me know if you're interested.

Eh? It absolutely did not do that thing.

So first of all, if you like D&D 3.x or Pathfinder 1e, I'm glad! It's a fun system. I have many great memories of amazing campaigns in that system, and I think it's most important that you play the game you like. But I've been hearing this "video game" thing for half a decade now, which means I've got a whole big rant prepared. I'm...I'm sorry.

Ok. So. Yes, 5e filed off all of the stuff that was interesting, the big numbers that make people feel powerful, the stuff that made characters unique, etc. in its pursuit of making D&D like a video game. But Pathfinder went the opposite direction.

• You can make 238,140 mechanically distinct level two characters based on ancestry, class, and archetype alone (that's not a random guess, I did the math); and while they won't all have the same power level, they will all likely be able to contribute meaningfully. And that's not even counting all the class-specific choices and options, or the other feats you could take. Paizo is six years into PF2e right now, and even though they had to waste a bunch of time dealing with WotC's OGL nonsense, they're up to nearly a quarter million different combinations; but 3.x didn't get anywhere near that level of meaningful customization until Pathfinder debuted archetypes in the APG in 2010---a full decade after 3.0 came out.
• The 3-action economy is so much easier to play and explain than "wait, what's a 'swift' action again?" (I've taught a seven-year-old how to play successfully), but it doesn't feel like a video game like 5e does because there are actual, meaningful choices you can make with each of your three actions. While 5e (and 3.x before it) often devolves into "conga line of death" (surround the bad guy for flanking, whomp him with your biggest weapon twice per turn, don't move because he'll AOO you into powder), you can do essentially whatever you want with each of your three actions and make a difference.
• Plus, where 5e aimed at making things even more same-y with "bounded accuracy," PF2e leaned into crits so hard that they had to lean into crit fails, too, in order to balance them. You can crit succeed and fail at skill checks, and the APs have rules for what happens when you do. Some weapons are built around crits, and they're not a 1-in-20 chance anymore. You can do them quite often with the right build.
• As far as setting, the Forgotten Realms were probably interesting back when Greenwood came up with them, but putting a billion authors into the world has made it into the same bland, boring, Wal-Mart-Brand-Middle-Earth that Greyhawk was; but Golarion has something like three different continents for every possible type of fantasy setting you might want (that is a random guess, and probably an exaggeration).

And with the addition of Starfinder to the system a few weeks ago, all of that gets doubled or more.

Plus, it's so much easier to run as a GM than the 3.x games were. I remember the first time I put a "hard" encounter together for PF2e. I looked at it and was like, "whoa, that can't be right, I'm gonna have a TPK!" So I nerfed the encounter, and the players stomped it in two rounds. When I built an encounter the next week using the rules as written, it was a fun and dynamic encounter that lasted the entire session. One character went down. Everyone used their consumables and resources. It worked perfectly. Ever since, I trust that the encounter math knows what it's talking about. When was the last time you were able to say that in 3.x?

Doesn't help that we've got metric tons of content in the old system.

A lot of the really good stuff has been updated for the new system, either officially or by the community.

Why retrofit what didn't really need fixing?

I mean...3.x was kind of janky. Yeah, it was better than AD&D, and yeah, it was awesome in its time, but it's based on a 25-year-old system. People know a lot more about game design now, and it shows. Pathfinder 1e did noble work trying to make everything fit together, but they deployed a lot of duct tape over the nine years they were essentially "in charge of" the d20 system. When the "Pathfinder Unchained" classes came out, and you could see the difference between a modern approach and an original approach at the same table, it was like night and day. Some tables even banned Unchained classes because they would outshine the PHB/CRB classes, even though their damage output was still balanced.

I don't think Pathfinder 2e is a perfect system. But it's definitely better than the 3.x rules. That thing did, in fact, need fixing.

Just give me more APs.

They have! And they're great! You just have to play PF2e, or convert them to your system, in order to play them. Or you can play third-party adventures, which are still coming out for PF1e/3.x as recently as yesterday.

Like I said, if you still like 3.x, I'm glad! Enjoy what you enjoy. I think it's most important that people play the game they like at their tables. But 2e didn't make it "video game-y."

It's only a TTRPG if you can win it in character creation. Everything else is just sparkling video game.

Not really, PF2E is its own system that is in the D20 family but no longer directly compatible with 3.X. However, since encounter balancing is easy, if you want to convert 3.X adventures to PF2E the work is pretty simple.

Is it still compatible with all the money I wasted on 3.x Hasbro D&D?

While technically the answer is "no", people who emphasize the difference don't apply the "Rule of Cool" as liberally as I did.

I re-used all kinds of D&D 3rd Edition resources while switching to Pathfinder.

Sure, we absolutely shouldn't just dogmatically use the numbers given in a 3E book with Pathfinder.

But I didn't find it terribly hard to whip up Pathfinder monster and NPC number adjustments based on my 3E source books, more or less on the fly.

Many numbers given are close enough. Most abilities are easy enough to convert in a way that is fun. The Challenge Rating isn't tuned as carefully, but i find the usual GM toolkit can address that. For example, throwing in a few extras baddies from over the hilldside can scale an encounter up, and awarding the players various story advantages "for good role playing" can scale an encounter's challenge down.

If my napkin translation went too badly, I threw "Rule of Cool" at it, and just made sure the players were still having fun.

I will say, I relegated 3E stuff to filler encounters, just as I do with anything else I homebrew.

I don't mind being on my GM toes for a quick encounter, or a short story arc. But I don't like having something poorly balanced have a recurring role in my campaigns.

All to say I have used 3E source books liberally in my Pathfinder campaigns, and I'm not sure any of my players have ever noticed.

GURPS Lite is available for free, and includes the basic rules on how to do things, combat, etc. It doesn't include the introductory "What is a GM?" stuff to save space; though that does show up in the Basic Set. You can extrapolate quite a lot from just what's in Lite - a lot of the stuff in even the Basic Set that's not in Lite is corner cases (how far can I jump? What can I shift or drag, instead of lifting?), clarifications (how long does it take me to dig a hole?)... and lots more skills and abilities!

Mook has some very basic combat examples worked through here

In a little different vein, Feral Sword Wielding Wizard has some fight scenes from movies he's gone through and labeled with GURPS combat maneuvers, so you can see how they work! (Just keep in mind this is with a bunch of optional rules!)

So much

https://www.sjgames.com/gurps/books/

If you like Actual Play shows, the Film Reroll podcast plays exclusively in GURPS. They play a fairly light version of the rules, but still make custom mechanics for various settings that show how modular of a system it is.

The show takes the premise of a movie and plays it out as a roleplay campaign. My favorite is Friday the 13th: The Final Chapter, in which the GM tells the players they're playing an obscure teen romance from the 80s so that they wouldn't know they were in a horror movie. I probably wouldn't recommend that for a table, but the actors know to expect tricks and it works very well as entertainment.