Yes I know about kodi but I have a few issues with that for one it has a pretty outdated ui but this is not a deal breaker for me but it also doesn’t allow the opening of other applications like Netflix or jellyfin etc, you have to install a compatible plugin.
Are there any gnu/Linux desktop environments that are optimised for a home theatre time situation to be used with a remote or game controller? At the moment I will probably just use gnome or kde but it doesn’t work well at all with remote or game controller.
libreELEC, but that’s just a distribution shipping kodi.
you might be able to utilize steam big picture/steamOS with different browser shortcuts and applications added as non-steam games to open streaming services in kiosk mode or other mediaplayers , that way you’d have good controller support, if you create control schemes for various things.