Kodi https://kodi.tv/

I wasn't able to find anything other than PeerTube. That is what I'm using, it's not great as a library manager because the filters are not meant for that, but it's better than enything else because when you upload a video you can tag it, have a title and a description and thumbnail, etc. and then you can search for it, it has a discovery tab and you can have different users on the same instance.

I use it mostly to store my and my families videos so we can share them between each others without making them public. There is a possibility to make them private, internal (only people with an account on that instance can see it, unlisted and public). I describe it in more detail in this video: https://tube.jeena.net/w/fyDDHo3P1qYrEH3HFk7FP3

I also use Plex, but it is definitely not FOSS. Jellyfin is a thing, the UI needs a LOT of work, though.

I prefer Plex mainly because it has allowed me to easily share to family without any real barriers except that the account information is controlled by a for-profit company. And to be fair to myself, I was a Plex user before it left the OSS world, back when it was a simple fork of XBMC. So I’ve been bought-in since its early versions.

Well, there's Stash. Here's a video demoing the main features.

Once you get over laughing you'll realize that if a person is very serious about organizing their video, this is actually a really great option.

I use Plex. I have different libraries set up for movies, TV shows, educational videos, home videos, and during the pandemic it was great because my kids were doing dance class remotely, so I even set up a library so they could have all their dance class videos in one spot to practice their routines. I also organize my family photos there as well, which works out great to have those and the home videos all in one place. I can even give family members access to various libraries if they want to view family photos/videos, which has been handy as well.

Lots of people swear by jellyfin, but I've had so much success with Plex that I haven't bothered to check it out. It's probably easy enough to get a server for each up and running and see which you prefer.