Video hosting is notoriously expensive. PeerTube circumvents this problem, because videos aren't stored on some single server, which would cause high bandwidth cost for the server operator, but largely by the users after they watched them, similar to BitTorrent. This way, the cost of video hosting is distributed among the clients, by using their internet connectivity for sharing.
I believe that PeerTube is an interesting project, and I'd ask you to check it out. It's cool.
Similar to Lemmy, it's not a single running server, but rather a software that can be used to set up a server. So there's many instances. I'm still exploring which instances are interesting. If you have any recommendations, I'd like to hear them.
With most videos on Peertube the server still has to do nearly all of the work. Optionally users can contribute bandwidth while they are watching but not after; how would that even work on a website that you close after watching?
Its a neat feature if a video goes viral or so, but Peertube still needs a lot of bandwidth regardless.
I want PeerTube to explode in popularity so badly.
My experience has not been great, though. I haven't found an instance that will reliably play back a video for me, yet. Bandwidth is a hard, hard problem.
If you go to "trending" or "recently added" it will say "scope : federated" near the top of the page. If you go to "local videos" it will only show local videos sorted by default by upload date. If you go to any of these pages and click "more filters" you can choose under "scope" whether it shows federated videos, whether to sort by popularity or upload date etc, which languages or categories to display, etc.
Still, it is difficult to find good content on PeerTube in my experience. Your best hope is probably using sepiasearch.org rather than the search feature of your own instance.