That said, I'd love it if Plex or Jellyfin were able to use that storage to cache files locally (eg. stream the data as fast as possible and play from the local copy) to smooth out some flakiness with the wifi between the tv and my home server.
I've used it for a total of a few hours in many years, almost exclusively for mini motorways. It never made sense to play over the Switch or PS5. I'm not sure who's using it.
I'd guess it's room for the AI model and future versions of it that could grow.
I would expect only mobile developers to actually bother porting games natively to Apple TV, with larger titles opting for game streaming.