u/Fizzys_Solution

If you want to skip my yammering the band is Man Man.
There's other recommendations here cuz I couldn't help myself but the section on Man Man is at the end if you wanna just read that bit.

Long ago I used this subreddit asking for band recommendations, there were a few I liked, Fish in Birdcage has some decent songs, Jiminy by Bear Ghost is amazing, and Exploitopia by That Handsome Devil is one of my favorite albums.
However, I grew tired from the reptation of hearing the same few bands recommended over and over. I decided I needed to go on a journey of enlighten, not just for myself, but for all the other Will Wood fans that couldn't expand their taste in music beyond Tally Hall.

What I found was amazing.
One of the first was That Handsome Devil, I had listened to a few of their songs but not much outside of Charlie's Inferno, then one day Exploitopia came out, that album is an absolute trip, go through the whole thing at once if you haven't.

King Gizzard & The Lizard Wizard, if you haven't heard of this band you're missing out.
Almost every album is a different genre of music, it's self referential and the albums have a story line that the community calls "The Gizzverse."
If you like Will's softer stuff Flight b741 is my personal favorite and has a lot of similar themes.
Nonagon Infinity is probably closest to Self-ish, but I wouldn't call them similar, if you're ok with Metal then PetroDragonic Apocalypse etc and Infest the Rats' Nest are amazing.

Guilty Gear is a fighting game with an amazing soundtrack, has a lot of Metal but also a bunch of other songs from wildly different genres, the older games are just instrumental but the newer one Guilty Gear Strive has themes for every character. If you've seen the meme with that one trans girl named Bridget that has "The Town Inside Me" song, that's Guilty Gear.
(like this song is just a Will Wood song and it's crazy)

Now... MAN MAN/HONUS HONUS

This band is crazy similar to Will Wood, like it's scary: They both play piano and are the lead singers, they both slam their keyboards, they both had a face paint phase of their live shows, they both used to be pretty crazy but have since mellowed out a bit, the themes of their songs are so similar they both have a song about doing drugs and losing your memory because of the whole Mayan Calendar thing (2012/Mayan Nights) some songs have some really weird lyrical overlap I've noticed

Bangkok Necktie
"I left my heart out on the table do you want it now?
Well there it goes right out the door to terrorize the town"

Against the Kitchen Floor
"Honestly thought nobody'd want it, let alone notice it's gone
And so I left it home, but now, now, now, now"

Laplace’s Angel
Am I bad, am I bad, am I bad, am I really that bad?
(It’s the norm for particles, eye for eye for tooth)
And now we're singing
Ooh, whatever you think of me
(It’s the norm for chemicals, it’s the norm for particles)
If you were in my shoes, you’d walk the same damn miles I do

Haute Tropique
You're born what you're meant to be
If you're bad, then be bad the best
If you're good, stay away from me
I'm a bad influence, I'm the best

Man Man has 7 albums, along with 1 solo album under his stage name Honus Honus, he was also in a band with Modest Mouse called "Mister Heavenly" that has 2 albums (side note I just found out about this other band a few days ago, and apparently Michael Cera was in it for a bit)
This band is so good and so similar to Will in themes and genre I am so surprised that word searching the subreddit I found one mention of them.
LIKE LOOK ME IN MY EYES AND TELL ME THIS ISN'T JUST A OLD VIDEO OF WILL WOOD?????

Here's a playlist of what I think is probably their best stuff off each album
Poor Jackie and Trunk Eyes are probably my favorite, and Cryptoad is the first song I listened to.
The way I listened to them was just going through the albums from newest to oldest on the Man Man account, then Honus Honus, then Mister Heavenly.