Steam has been rolling out the support of the DualSense controller over the past weeks. In the beginning, the support for the controller itself was added. After that they worked on the addition and refinement compatibility of advanced features such as trackpad, rumble, and gyro. DualSense’s adaptive triggers are probably still being worked on since Valve did not give out any information on this matter.
Games that use Steam Input API should work with the PS5 controller now with no work required from the game developers. Valves API system supports over 200 controllers which include rave wheels and dance pads, as well as traditional controllers like the Nintendo Switch Pro Controller and PS4’s Dualshock 4.
Valve has mentioned that the use of controllers to play PC games has more than doubled over the past two years, and the biggest increase comes from those using PlayStation controllers. If you want to try out the functionality, opt into the Steam client beta and connect your controlled via Bluetooth or USB-C cable.