I'm only sharing access with a few friends and family, so I don't find it cumbersome. Usually I make their account using the Jellyfin app on my phone. I do sympathize with not wanting to do support, which is the main reason I don't even ask for help with the hosting costs. I don't want to feel any obligation.

Docker isn’t hard if you use a compose file. It’s easy to read syntax.

This is giving me "yaml isn't hard to use if you use a compose file!" It is, actually. It's easy for you because you understand the technology. The vast majority of people do not.

It's quite easy without docker to get lots of it running with a dietpi install. Runs on rpi and alike, but also on any "normal" old low end pc. Just select jellyfin, arrs, ... It handles it all for you, no need to learn Docker (I know people will argue about the advantages of docker, which are valid points, but ease of installation is more important to many people). The only difficulty remains the streaming outside your own LAN (because it's risky). VPN, tailscale, ... there's options but it always keeps on feeling risky to open up outside LAN. Local setup for jellyfin can be really really easy tho, if it's just for yourself and you mostly watch at home anyway... And in some jellyfin compatible app like Finamp and Streamyfin you can just download a few music albums, episodes or movies to your phone before you travel...

I've got to admit that I've never used Plex (I'm a cantankerous open software fanatic), but how do you get your media on there? You're hosting your own server so presumably you're downloading the media somehow. Are you doing it manually? If so, you can do the same with Jellyfin. Is it automated with some tool built into Plex?