I feel like the article is extremely subjective, so I figured it'd be more fun to post your own top 10 good/bads.
I'll start with mine.
Sleepy Princess in the Demon Castle
Dark Gathering
Ya Boy Kongming!
Great Pretender
Summertime Rendering
Miss Shachiku and the Little Baby Ghost
Diary of Our Days at the Breakwater
Uncle from Another World
Digimon Adventures (2020)
Muteking the Dancing Hero
I tried thinking of anime that I'd suggest to friends who are already fairly active watchers, but for some reason or another had them slip through the cracks.
Bang Brave Bang Bravern - Big gay robots. Hilarious show.
Skip and Loafer - Succeeds more than any anime I've seen at making the characters feel like people.
Keep Your Hands Off Eizouken - Fun story about making anime.
Vivy -Fluorite Eye's Song- - The only "robots rebel against humanity" anime I've ever liked.
ODDTAXI - An excellent story about a guy who gets wrapped up in some shady dealings he'd rather avoid.
There's been some other great stuff too of course but I wouldn't say that anything else I've seen that's been released since 2020 has been overrated underrated.
As for worst it's gonna be hard to beat The Legend of Heroes: Trails of Cold Steel - Northern War and Ex-Arm.
I tried to split my list genres so there'd be a bit of everything, but I definitely agree with most of yours. My only gripe is trigun.
I understand how they took the source material and completely warped it to attempt to fit a new story and give it a whole new life of its own, and minute to minute the show is fine, it's when you look at the whole story being told at once that things start falling apart and giant plot holes start showing up. Particularly in the first half of the season. The makers wanted a spectacle more than anything else and they delivered on that.
I haven't read the manga, which my understanding is what the reboot was following. I watched it now out of curiosity, due to the original anime being one of my main gateways to anime as a whole.
If I hadn't seen the original multiple times, I probably would have been lost at multiple points in the reboot. Characters seemed to pop up out of nowhere for unknown reasons.
My girlfriend had never seen the original, and she originally wasn't paying attention as I watched this on my own, but after a few episodes she got pulled into it as well, so it seemed to make enough sense to someone unfamiliar that they'd at least be curious.
I enjoyed it mainly because it got me to think so many new things about one of my early favorite anime universes. It filled in a few gaps I had, such as I liked how we got to spend more time with Project Seeds and learned more about the Plants species and Knives' overall goals.
It made my list because it exceeded my expectations as I was not looking forward to CGI animation and I was concerned about them "ruining" the story I had in my head, but the animation was beautiful, VA was great, and I think about the universe of the story more than I have in years.
It's totally subjective what anyone else will take away, but everything else on the list I went into blind, with no expectations. Trigun I came into very biased due to my love for the original, and expected eww to meh, but as a whole, it gave me a great time.
Not sure if its underrated but Vivy -Fluorite Eye's Song- was one that I didn't hear a whole lot of buzz about but is one of my favorites in the last few years!
That was more my impression, but I don't follow ratings or reviews much, so wasn't sure. I just know that I rarely see it discussed, but pretty much universally positively when it is.
I did not expect to love VTuber Legend as much as I have this season. I only vaugley knew about Hololive culture beforehand, but I still loved (and will love for the next couple weeks) every joke that's come out of that show.
I generally watch the first episode of every new anime (and have been since the beginning of 2020).. The Vtuber one didn't especially catch me in that time, but it's not the first to slip through the cracks. I'll give it another go.
Based on the difference between average score and my rating on AniList, some of my favourite underrated anime of 2020s are (sorted from largest to smallest delta):
Bofuri is a good answer. That show was such goofy fun. Also, I am not surprised to see 100GF there. So many people will write off shows just for having a harem tag. So, when a show comes along that is the harem-iest of harems, they don't even give it a chance.
Love After World Domination - A cute romcom between the red ranger and one of the evil organization's leaders. I will always lament the early cancellation of this manga, but the anime was great as well.
Reborn as a Vending Machine, I Now Wander the Dungeon - Most people dismissed this show based on the title, but for those that actually watched it, it was surprisingly good. Not amazing...but definitely fits the underrated moniker.
Endo and Kobayashi Live! - A villainess series that is just full of fluffy romance. If you like tsunderes, then this is right up your alley.
Chillin' in Another World with Level 2 Super Cheat Powers - A series that starts with a painfully generic episode 1 before revealing in episode 2 that the actual genre of the show is romance instead of any kind of power fantasy with no harems allowed. A lot of people dropped it after just the first episode.
TSUKIMICHI -Moonlit Fantasy- (and season 2) - Not sure how underrated this is, but I really enjoyed it, even as a source reader. I feel like this series has a small but dedicated fan base in the West.
Level 1 Demon Lord and One Room Hero - This is a very silly fantasy show about a hero that has let himself go in retirement. As the show goes, it builds to some real touching, emotional stuff, but you just need to get through some fan service on the way there. Way better than I thought it was going to be.