First, YouTube Premium costs a shitload more than Nebula. Using Australian prices, YTP is $15 per month. Nebula is just $30 per year.

But second—and this is just me, I can't speak for others—I did pay for YouTube Red, back when it was called that. But I've long been annoyed at all the many ways YouTube is hostile towards its creators. The way their copyright system goes so far above and beyond what's actually legally required, and how that so frequently works against creators. They seem to have just given up on the notion of fair use entirely, they've had a history of even allowing copyright claims on things that are uncopyrightable like public domain NASA footage, because some copyrighted news footage used it and tried to claim it against others. And the people who abuse the system never face repercussions. Creators do. The final straw for me though, and when I decided to turn off my Red account and start using adblockers, was when YouTube decided to change the definition of who was eligible for the partner program and this monetisation, cutting out smaller channels entirely. That pissed me off, and was when I said screw Google.