I'm a professional C++ dev working in games, and windows is used everywhere , from games themselves to the network infrastructure(I've worked for 3 of the largest games publishers too).

Windows really has a fantastic support for C++ and rendering programmers imho, the tooling is world class and Visual Studio has no match as an IDE. Even if somehow my tools worked on Mac or Linux I'd still pick windows out of sheer convenience of using it for work.

But as things stand - all major console toolchains are windows only. If you're making a game for PlayStation, Xbox or Switch, you have to be on windows.