SteamOS is an immutable Linux distro that is designed designed to be usable without a keyboard / mouse. By default, it boots you into something that's like an optimized version of Steam's Big Picture mode (but with less compositor / desktop environment overhead).
From this interface you can launch games, modify all your settings, pull up performance metrics, change refresh rate, change your CPU / GPU TDP, enable FSR or other scaling methods, etc. all using just a controller with no assumptions about you having a keyboard / mouse handy.
You *can* launch into a regular desktop environment optimized for keyboard and mouse whenever you need to do certain things on it, but the main focus and value add of SteamOS is the controller friendly interface, and lightweight, resource optimized environment.
From this interface you can launch games, modify all your settings, pull up performance metrics, change refresh rate, change your CPU / GPU TDP, enable FSR or other scaling methods, etc. all using just a controller with no assumptions about you having a keyboard / mouse handy.
You *can* launch into a regular desktop environment optimized for keyboard and mouse whenever you need to do certain things on it, but the main focus and value add of SteamOS is the controller friendly interface, and lightweight, resource optimized environment.