@kravietz
Because there is no quality content on peertube (or content at all). It's the classic snowball case. People start uploading content, your popularity rises, more people upload, and you become a reference platform. Since you are reference, everyone uploads to you, other sites get no content, and to be heard, all people must come to you, or no one notices.

Peertube has no content. It is no alternative right now. Maybe in 5 years, but not now.