While I agree broadly with what you are saying, your comment ignores the externalities that society puts upon people that causes a lot of these feelings/habits/behaviours.
We still should do our best to not be this defeated. We should absolutely do our best to take care of ourselves mentally and physically, but for many this is far easier said than done because of the externalities.
FWIW, the jellyfin flatpak is the official client from jellyfin and has all the codecs baked in. I run it on my arch (BTW) install and havent been having any problems.
This sounds awesome. I'm going to read this tomorrow when I can give it my full attention.