My go to OS is Nobara KDE which is a gaming spin of Fedora. It has the best compatibility out of the box for my stuff. I'm sure other distros would word too tho.

Most used apps are Firefox for streaming, Steamlink for playing games from my gaming pc, Retroarch for psx and snes gaming and kodi to watch the content on my local network

Interaction is with a keyboard like this one

Downside is obviously that it is less plug and play than a commercial media product. You need to set up everything initially, you need to update it and sometimes an update breaks something and you'll need to fix it

Upside is awesome tho: no walled garden. It's your gadget. You can do anything you like with it. No app is gonna track anything you don't want