Look, I'd love for Peertube to rival Youtube (and it's a growing platform, who knows what will happen in the future), but like you said, there are very few content creators and mainstream personalities there. Try looking up a song, a clip from a popular TV show, a game walkthrough, a stand up from your favorite comedian, a silly meme, whatever, and if you find anything on Peertube, that's impressive, but on Youtube you'll have dozens upon dozens of examples. The difference in scale over popular content makes any usability comparison right now just wishful thinking. This has been by far YT's (and maybe on a larger scale Google's) strength: everything/everyone is already there, so why go anywhere else, where not nearly the amount of people will be watching and bringing in money based on those views.

Still, I'm hopeful people will accept alternative platforms more and more, with how shitty the YT experience has been on the official client and I enjoy discovering new channels I can follow on Peertube, but as of now, I don't think most people could ditch one for the other, realistically.