Mostly braindead content and channels with mixed political undertones—all things considered, they'd probably be divisive here, so I've selected the more neutral ones that I actually find useful/enjoyable. Send me off to the Recovery section for some of these, I guess.
-No Lab Coat Required. (Nutrition)
Kiana Dochterty also has some interesting stuff on the same topic.
-Shaelin Writes. (Writing craft advice, but imo more effective than most bigger channels.)
-easy, actually. ("self help", but mildly less annoying; your milage may vary)
-Marc Brunet (art lessons, though I don't draw anymore I found his advice to be most helpful of all the channels I perused)
-Ethan Chlebowski (nutrition/health/cooking advice, mostly taught in a foundational way.)
-Kurzgesagt
-Vibracobra23 - Music based. Just a massive collection of Peel Session tapes in one place, but I thought it was also worth mentioning.
I also love DarlingDollz, but that's way more niche (doll collecting). I hate the annoying community and personas around these channels, but for once, his are relaxing; and when it comes to doll history, nicely presented.