The green tick may give the impression that the game runs just as well on Windows. In reality, there have been issues with CS2 on linux recently. Even though its officially supported, It may look like Valve doesn't have good enough testing to actually ensure that. I tried it on Fedora KDE with wayland and nvidia and it crashed after one match (if not in the middle of it). Similar issues have been reported on the issue reporting repo. It may be an Nvidia+Wayland issue again (like there have been so many times before).