Is a domain name strictly necessary though? You would need a static IP. I thought you needed something like a VPS or VPN — I know what a VPN is, but I think it was something with a similar acronym — and that was a service that cost money.

With Plex it just works. When I load up Plex on a remote machine, first it tells me my server is offline, because my server is a Mac and Macs are sleepy bois, so it wakes up the Mac, which wakes up the drives, and then the server loads up and I can play pretty much anything.

I've ran Jellyfin on both Mac (current setup) and Windows/Intel. I like Jellyfin overall, and it does some cool things Plex doesn't. Like you can fix details Plex won't let you. Like for some reason it only lists the foreign actors in anime, you can manually specify the English voices if you want. Plex doesn't let you do that and AFAIK there's no way to. (There should be an API out there that taps into a service that lets you access any language cast, and there should be a way to set it to dynamically change the cast to whatever language you have selected.) But anyway, Jellyfin is somewhat fine, but to use it on other devices (e.g. an Apple TV box on the same network), you have to do a fair bit of configuring. It's not just, log into the account on your phone and type in the text on the screen. Jellyfin doesn't even prioritise Apple development, but they have come a long way.

Sorry to be a pendantic ass. But. Jellyfin, in and on itself, has absolutely nothing to do with docker.

Rumor says that Plex also denies you remote access when you use a VPN or mesh like tailscale… so ymmv

Never had any issues remote streaming via VPN.

I've accessed my Plex off network with tail scale 🤷

You should at least figure out port forwarding, but Plex operates a service that makes that optional. You don't have to do that or setup a reverse proxy with Plex, it mostly just works near seamlessly.

I've never opened a port for Plex.