Yeah, but that requires Steam to add support for those input events. It doesn't have an API for you to feed it input events. There's not exactly a standard for random input events for Steam to hook into either.
That's why distros like Bazzite and ChimeraOS have an additional translator[0] to take input events and output a controller that Steam supports, Dualsense edge or Steam Deck's controller, to be able to add support for gyro and back buttons.
[0] https://github.com/hhd-dev/hhd or https://github.com/ShadowBlip/InputPlumber