On further consideration, I think I can whittle down my "hidden gems" recommendations to 2 channels:
Dance/Electronic composition, arrangement, and production
- https://www.youtube.com/@Bthelick/videos
Music Theory Essentials
- https://www.youtube.com/@DavidBennettPiano/videos
Bethelick
If you are trying to make dance music of any kind (especially any flavor of house), Bethelick is gold. They use Ableton Live for all videos, but what they are teaching is equally relevant to every DAW or hardware sequencer.
There is zero fluff, no eye candy, no algorithm-gaming BS, no faces, and no "one simple trick" charlitanism. It's just hours and hours of all the things I wish someone could have shown me when I was first getting into electronic production decades ago, broken down into topical lessons.
This channel does a good job of taking the time to explain any music-vocabulary words they use in-context, as well as covering some theory concepts as-needed, but anyone who feels less-confident on that front should also check out:
David Bennett Piano
Despite having "piano" in the name, these are musical vocabulary & theory lessons that apply to any popular genre and any instrument.
There are a ton of theory-focused channels on YT (yay!), but the way David presents and illustrates each topic is (in my opinion) the best there is right now. Whereas more familiar faces like Rick Beato or Adam Neely are explaining things in a way that requires you already have a decent theory foundation (which is a fair assumption, given their audience), David makes no assumptions about your prior understanding, but get's through the topic at hand without wasting a ton of time re-explaining fundamentals.
Personally, I consume a few different theory channels that treat Hard Bop like a competitive sport, but when I want the clearest and cleanest way to explain a given concept, and illustrate it with examples people will recognize, I turn to David.