I don't watch YouTube because almost all content it offers is low quality. Staying away from it seems like the best strategy, especially considering that YouTube can be defined in two words — spying and censorship. I can't recall any good language learning content ever posted on YouTube. If you want to familiarize yourself with language learning theory, search written guides online. It will take you less time to go through them because reading generally is faster than listening. The obvious examples are the AJATT site, Antimoon, the Norsk experiment and this site of course.
Specifically language learning YouTube channels are never about immersion learning, so there's no reason to ever watch them. Instead, they try to learn languages using blue-pilled methods. In the past there were some YouTube channels making "ajatt update" videos where people documented their progress learning Japanese and other languages. I don't see those being around anymore.
When it comes to immersion content, however, YouTube can offer something you'll like. Things like streams, podcasts or news are good to listen to, especially for passive immersion. Explore the YouTube guide for details.