Jurisdiction isn’t simply determined by where the opponent is. There’s nuance to this but you can typically sue and gain jurisdiction in any venue that has a nexus to the business activity in question. Given that YouTube is global there’s probably a lot of places you could find a valid venue. California almost certainly being one of them.

You might have trouble getting the opponent to cooperate but if your ultimate goal is to get YouTube to do something then that could work just fine.

Again, clearly legal action isn’t easy but people seem too inclined to throw up their hands instantly.

Learning how to take basic legal action is just a core part of running a business, and someone earning from YouTube at this level is indeed doing just that.