I read sites that are for system administrators (I don't know why, I'm a coder) and the majority of their posts are Windows, Azure or other Microsoft technology specific.
I know IBM has Linux, or did 10-15 years ago, across the org, around maybe 30% used Linux on the desktop even in Marketing. I don't know if it's still the case there.
It makes me wonder if there are any fully, just Linux corporations, no Windows.
I don't know if this is still the case but Redhat had strict rules requiring all servers and desktops to be RHEL. By strict I mean they boasted in front of my coworker and other customers there for the RHCE and their own employees that anyone deviating would be fired on the spot. But this a long time ago RHEL3 timeline.