This probably isn’t what you’re going for, but my family all use our gaming PC running bazzite for this kind of thing. We use Firefox and have bookmark bar links to plex, immich, etc., and we all just use the same system account, and some of us have our individual steam accounts. Use it with a blueooth mouse and keyboard, and game controllers. It’s not tiny, and using the keyboard and mouse is bigger than just a remote, but we get to type on a real keyboard, we get to point with a real mouse, and we don’t have to fight with all the app limitations that would come along with a more limited device. Been doing this for like a year or two and nobody has complaints. We sometimes still use our xbox in another room, but it’s pretty rare. Using a real PC for this kind of thing is just a better experience.