I've been an ios user for 100 years at this point, but used to be deep in the android scene before then. I've just got an android for a work phone and am wondering what's changed in the last 10 years - what are your essential apps, settings, customisations? I've had a hunt around xda but can't seem to find much in the way of roms for my model (Samsung A04) - back in the day it seemed there was a thread for every device!
Niagara Launcher is the coolest thing I've seen happen for mobile interfaces since the first touch interface. It is so clean and well-designed, it makes everything else in iOS and Android look like a cluttery mess - all while adapting to what you need and offering quick access to everything on the phone.
Google's a much bigger part of the ecosystem by default. Used to be the Google app store was a selling feature, now Google is integrated into pretty much every device (and has contracts with manufacturers to force that).
It's also, like Shortwavefilter mentioned, much harder to root or flash a devices.
Though the AOSP has gotten better in ways too. It's gotten a lot better hardening, and still is fairly open (e.g custom app stores added one click).
Last, there's still plenty of bloat pre-installed on some brands, but I think that was the case a decade ago as well if my memory is correct.
Honestly I can't think of too many essential settings or apps that'd be a necessity for everyone. Usually I'd say change privacy settings and disabled as much bloat if you're not using a ROM; but that might not be applicable if you're on a work phone. Apps wise, I'd say stick to open source if you can for the basic offline utilities -F-Droid is great for that if you're allowed to install it.
cant really say whats essential as thats on a per user basis, but stuff that has made my experience enjoyable include f-droid, aurora store, and youtube revanced.
You can add a private DNS in the settings. It'll allow you to have a dns level ad blocking experience without having to use any of the dubious ad blocking apps. You also don't need root or a VPN.
I'm using my own dns server, but keep in mind that it needs to support DoT. You can't just enter any IP, because of the certificate check (the dns requests are encrypted using TLS).
dns.adguard.com works, but as is the case with all dns services, they will be able to see every domain you access. So keep that in mind.
Well, any samsung with a snapdragon chip is pretty useless for ROMS. To ROM these days you need a Google Pixel (best supported), OnePlus (most models), or Motorola (some models).
For some privacy/security features: "Warden" allows you to block Trackers and Loggers on individual apps, if you have root. "TrackerControl" or "Rethink: DNS + Firewall" basically allow you to customize a Firewall and in the case of Rethink also offer a good DNS service. I basically see no ads anymore, even in other apps.
If you run your own Plex server, Plexamp is a fantastic music player. You do need to have a Plex Pass subscription or lifetime pass though.
Aegis and Authenticator Pro are good choices for TOTP two-factor authentication. Both are free and open-source. Authenticator Pro supports WearOS which I like since I can get my 2FA codes on my watch. Aegis is very principled and don't allow any non-open-source code in their project. I really respect that, but it does mean that they don't support watches, as supporting WearOS requires using a closed-source SDK from Google.