Generally I recommend -- like with Chromecast -- using your phone to launch and control apps, using your phone as the locus of control. Maybe having a gyro mouse or Bluetooth keyboard connected to your pi... but the originally Chromecast was input less, was a networked output. To cast a thing was just to tell the display or speaker: go to this URL. And then to have some communication channel open from your phone or casting computer to the display or speaker. Any web page can use Presentation API to start a cast, to extend itself to another device. It's amazing. https://developer.mozilla.org/en-US/docs/Web/API/Presentatio...
Under that model, there is no remote. The phone is the remote.
To run a regular TV is harder. Yeah I don't recommend trying to host a whole media system. You can run jellyfin on many TVs or maybe plex. Some rare brave souls go and build their own castles in the sky. Personally I feel strongly though that people clutching at remotes & making the tv itself the locus control are doing it wrong and that the cast model is fundamentally much better, and that the tv itself ought be a blank slate. https://arstechnica.com/gadgets/2024/07/broken-linux-laptop-...