I only tried one game, but I just tried plugging my PS5 controller into my PC and it worked without needing to install anything in Mass Effect Legendary Edition, and Steam is not running so it isn't Steam Input handling it.

My PC may have installed something on its own, but I did not.

However I don't have an issue if there is a driver, the requirement of Steam running and apparently launching the game through steam is the issue here.

Edit:

I just realized I completely missed the not in your message:

> I can confirm that you do not need a Sony/8BitDo user account or any of their software running in the background for the controller to work.

so I guess my reply was not necessary, I need more coffee...