In all honesty I don’t understand how PeerTube is supposed to scale with users once it gets content. Hosting, transcoding and streaming video is super expensive. There’s also a matter of making money from videos and without financial incentive it’ll be hard to compete with commercial solutions (in a capitalist hellholes that most of us live in). Community funding can keep up with hosting text but can barely keep up with hosting pictures, let alone something more, unless you’re an internet archive or something.
People who are on Nebula already made it in Youtube and they’re so big that they just want to make more money. They provide nice service for the money but I don’t think they will come support your revolution for free.