Most tvs have multiple HDMI inputs, why not have your Windows PC for gaming and a Linux PC with Kodi or whatever you like.
I personally just run mpv on my Linux box plugged into my TV and connected to a DLNA media server in my home and use my Android phone as a remote with KDEConnect, I'm not a big app person. I mostly watch YouTube videos my media server auto downloads when they are available from creators I like. For my family I have Netflix.
You're right it's not as nice as using a TV remote though! I bet Kodi or Plex, etc. would be more navigable with a remote. I wonder if you can get a Bluetooth remote that connects to a PC...
The shield remote does use Bluetooth I believe, I haven't dug into its internals though.
I kinda imagine that a "real solution" would involve some kind of Android environment, though. Your solution works, if the user has not opted into the youtube/spotify/netflix ecosystem. If they have, it's not a real solution.
I care about my youtube account -- I pay for it, in fact. The recommendation engine is extremely good if you curate it, and I've curated it a ton. YouTube is a beast for knowledge/learning center. Spotify has a really good and extensive music library which makes "not pirating" a real option.
At the end of the day, you need a good UI that implements the features of those services. No third party is working full-time to implement these in open source, and they'd likely shut down if they did. So relying on the upstream apps somehow makes sense.
I personally just run mpv on my Linux box plugged into my TV and connected to a DLNA media server in my home and use my Android phone as a remote with KDEConnect, I'm not a big app person. I mostly watch YouTube videos my media server auto downloads when they are available from creators I like. For my family I have Netflix.
You're right it's not as nice as using a TV remote though! I bet Kodi or Plex, etc. would be more navigable with a remote. I wonder if you can get a Bluetooth remote that connects to a PC...