From one of the Jellyfin devs in the issue you linked, posted in April this year:
Now, let's address this clearly once and for all. What is possible is unauthenticated streaming. Each item in a Jellyfin library has a UUID generated which is based on a checksum of the file path. So, theoretically, if someone knows your exact media paths, they could calculate the item IDs, and then use that ItemID to initiate an unauthenticated stream of the media. As far as we know this has never actually been seen in the wild. This does not affect anything else - all other configuration/management endpoints are behind user authentication. Is this suboptimal? Yes. Is this a massive red-flag security risk that actively exposes your data to the Internet? No.
At this point, this over-4-year-old issue has gotten posted to HackerNews more than enough times and gotten quite enough unhelpful peanut-gallery comments like those above.. We are limiting this issue to Jellyfin collaborators only at this point. Most of the big items are already tracked elsewhere (specifically, unauth playback) or have already been fixed. And many other options are now open to us in a post-10.11 landscape now that we have a proper library database ready.
The main difference between Plex and Jellyfin is the network setup. Plex takes care of that for you, while you have to set it up your self with Jellyfin.
Another difference is that Plex can combine content from multiple servers ( I think. I'm not a plex user, so I don't know for sure), while it will always be seperate servers in jellyfin.
Jellyfin will always have my heart though, because it's open source and not here to make money. Plex also have a reputation to show ads and other stuff from streaming services.
I went:
Pi 2 -> Pi 4 -> Odroid H3 -> Intel N100 box (current).
All in all from about 4W idle on the pi to about 10W idle on the N100 box. So not a big power jump all in all, but my needs did get bigger since the Pi.
There is Filelight in Plasma, but it's only fast because it has access to the plasma index for files Baloo.
I use ncdu extensively though. Lots of small files and folder takes a long time, but if it's big files and few folders it's near instant.
There still a performance delta of about 30% vs windows for some of my games.
I know Proton is often touted as the magic beans that evens out performance between windows and linux systems. But most games will likely still perform poorly on Proton compared to WIndows native.
So the question is. Does this performance gap matter in the games you play?
If I can still play and have fun playing the game, then it would not matter to me. If you play competetive, where that performance does matter, then stick to the system that has better performance. Even if it might be Windows for some games.
From one of the Jellyfin devs in the issue you linked, posted in April this year: