Not everybody is so kind. In Germany, for example, lawyers are quite quick to issue cease-and-desist letters, which always involve costs. I’ve heard of Friendica instances that have already run into legal problems because, for example, copyrighted images were posted/federated. You’re being a bit too naive about that.

The lack of monetization is certainly one reason. On the other hand, YouTube was already successful long before monetization existed.

Sure, discoverability is another reason why PeerTube isn’t progressing. But I was more concerned with why it might not be successful even then. And the lack of content is indirectly related to my argument.