When I worked in VFX it was mostly Scientific Linux. A few macs were around for concept artists using Photoshop, and editorial using a proprietary video codec with Final Cut. Most business folks (in vfx called “coordinators” and “producers”) used tools that were web-based and cross platform (for example, Autodesk Shotgrid, Confluence, and Jira). A lot of internal development is done in Python so no worries there, either.
In game dev unfortunately it’s exclusively Windows. If you bring up even using os.path.join, instead of hardcoding \ into paths, devs who have never worked in another OS look at you like some sort of paranoid maniac.