If you want to break out of the windows mold, tiling windows managers are where its at. You’ve already explored that route with i3, and there are other alternatives, but they all have a bit of a learning curve unfortunately. hyprland might be worth a try. I’ve only dabbled but I did remember it being a bit more beginner friendly than i3. But be prepared to be confused, read a bunch of forum posts and edit config files for a bit.

While jellyfin itself is very simple, you might run in to problems if you want to use it while not on your home network. For this you’re either wanna use a VPN (or tailscale) or use something like nginx to give your server a web address, while you get this for free if you use plex.

Giving yourself a public address might be easier for the person trying to access jellyfin, but it it comes with a bunch of security considerations and you probably (definetly) want to do some research on the inns and outs of that. I would recommend tailscale but either way it’s gonna be some extra fiddling, unless you already have something like that set up.