EGS sucks, but the problem here is the ps5 controller. Sony very deliberately makes their controllers a fucking nightmare to use on PC and Valve had to do a ridiculous amount of very dodgy hacks to even get any of them to work a little bit with steam games. Turning the "PlayStation controller support" button on in steam literally only works by injecting code on the fly to make the computer think it's an Xbox 360 controller so that games will even see a controller present, and you still need ds4windows and other tricks to get it to even show up to steam half the time.
This sucks because you're using a controller with not only no PC compatibility, but negative PC compatibility because the controller's manufacturer has put in active effort to make it unusable. If you want to use a PC controller, you'll have a better experience with almost any other option. I can't speak for really weird knockoff controllers from brands nobody's ever heard of, but I'd imagine at least some of them have windows compatibility.
Unfortunately, if you want a PC controller that works, you're going to have to buy a different controller.