Went on https://peertube.video/ and immediately got a bunch of porn. Not really sure from a consumer aspect this is yet fully there from a UX perspective! But the tech is really interesting and as a federated alternative I could see it doing really well. Best of luck to the team!
Anyone can start an instance and post whatever they want. Just because it has "peertube" in the URL doesn't mean it's an "official" instance or anything like that.
Therefore their mental model will equate Youtube (a service) with Peertube (an application used by multiple services). If illegal content is on some Peertube, it's "on Peertube" and it drags down all the other stuff that is "on Peertube". Just like how big advertisers withdraw all their campaigns from all of Youtube when a single popular Youtuber posts a particularly distasteful video. They don't recognize the substructure inside Youtube's community because, to the public majority, Youtube is a monolithic thing. It's going to be the same for Peertube. (Unless Peertube has a better marketing department than behemoths like Youtube, which it likely has not.)