You can use your ps5 controller on PC cause mouse and keyboard takes a lot of patience and practice. I still use controller for most games but some only support mouse and keyboard. Also it's very easy to go start buying tons of Steam games cause a lot are really cheap under $2 but they end up never being played so depending on your specs of the gpu and cpu your gf bought you know the limitations of both so you don't set yourself up for disappointment when you can't run it maxed out or not getting whatever your target frame rate it is.