I’ve never had any issues with jellyfin. Maybe your use case is outside of what it’s for, but for watching series and movies it worked with everything I could throw at it for me.

Somehow my Jellyfin Android TV app became incompatible with the server application on my home PC and I can no longer watch videos, so had to head back to Plex or Kodi+NFS mounts.

you've most likely never tried to view subtitles. It's well known that its subtitle support isn't so good (to put it lightly). It seems to be unable to stream subtitles out of an MKV itself and has to extract them and send them separately. (or at least thats what it seems like from observation).

Same here.

Jellyfin is good aslong as the content is not HDR and needs subtitles.... Also the chromecast support is very non-wife friendly

I use subtitles all the time and they work really well for me - both embedded and separate files. I'm streaming from an SSD though, maybe that makes a difference?

Jellyfin works perfectly fine with subtitles.

But if you use ASS subtitles, which are entirely unspecified and unsupported and only have a single working implementation that requires half of Wine to work correctly, well, then you're fucked.

The only problem with subtitles I've encountered is the Roku Jellyfin client does not support VOBSUB subtitles which is annoying.

Kodi -> jellyfin -> a4k subtitles addon. Never transcodes

Works on Android devices like the shield or libreelec on something like a pi.

Those native Android apps, be it jellyfin or plex dont handle subtitles wel, be it .srt or .ass

You were likely unlucky with the client you used. I host a small server for family and friends. Some seem to go great (browser, roku, android(to an extent)), but others seem to have a whole myriad of issues. I've ended up just putting a roku in the hands of people i give access to.

That could be it, the client is LG webos so not that popular.

Same. I have plenty of issues with it.

I've used clients on all classes of Apple devices, LG WebOS and browser. They're all quite problematic.

I still run it alongside Plex and give it a go every month or so but the same or new problems always arise.