There is absolutely nothing necessary about the steam controller. Everything can be done with other controllers or input methods. We have steam input available.

I’ve used the deck and Linux in general on TVs and in desktop setups. I pretty much always need a keyboard and mouse handy for specific things or specific games. Just makes it easier… like it’s always faster to type text on an honest to god keyboard than any other input methods from voice to motion to touch to sign language. A wireless keyboard is about the same price as a pizza where I live.