Proprietary software I use on a regular basis with no Linux alternative:

Revit, AutoCAD, Houdini, 3dsMAX, SolidWorks, Rhino, Grasshopper, Adobe Illustrator/Photoshop/InDesign (and/or their Affinity alternatives), CUDA optimized simulation and rendering plugins, etc.

I use at least one of these every day, almost none of them have any functioning compatibility with Wine or other emulation. Even just using Affinity has caused some issues with team projects when someone picks up where I left off and there's no layer information and a ton of clipping groups instead.

If all you do with your computer is program, work with documents, use a web browser, and play video games sure go wild don't use Windows on any of your machines. But I just don't understand how some people in the FOSS community cannot fathom that there are entire professional workflows and industries that just have zero possibility of moving to Linux.

Do I like using Windows? No. But I do like being able to use all the programs my work and research requires.

I contribute actual, tangible research into FOSS CAD/CAM/BIM software development and implementation. I love it and want to see FOSS options grow and become widely adopted. But it just isn't anywhere close to having feature parity. And that matters, just as much as industry interoperability matters.

I'm just so tired of this thought process in the community that the only reason someone isn't using Linux/FOSS is because they're some fanboy or something