It's not an alternate way to view Youtube, it's a totally separate service. You're not missing anything, if no one's using it to post content, then there's no content. Youtube is a tough one to compete with because the infrastructure needed to host that much data and distribute it is insane. Peertube is super niche and not many know about it, but I do wonder how fast scaling would become a problem if it suddenly got an influx of new users.