That said, Valve already has a strong control input solution in the Steam Input API, which already removes the onus from developers to support many different controller types, so it's unlikely ...

“Steam Input API offer gamers a significantly enhanced experience with a limited developer investment.” – Seamless player experience with correct glyphs for all devices, including any remapping.

The latest Steam client update added full support for Sony's fancy new controller. Valve just rolled out a new update for Steam, which includes further controller support in the Steam Input API.

What can you do — Steam Input API games reportedly have the full support of the controller's LED, trackpad, rumble, and gyro features, but no mention was made of adaptive trigger support.

The Steam Input API already supports over 200 input devices, including the PlayStation 4 controller, the Nintendo Switch Pro controller, fight sticks, race wheels, dance pads, ...

The latest patch has upgraded the controller-friendly hub on Steam to make it easier to sort by controller ... and there is also a new category for games that make full use of the Steam Input API.

Update (11/21): Valve posted that games using the Steam Input API should know have full support for the DualSense features mentioned above (basically, everything except adaptive triggers), ...