Even as a workstation - I already pointed out that Adobe and Serif won't port their apps to Linux. And that's one example of a professional use case. Think about the doctors, lawyers, technicians, sound engineers, video engineers, who all need to use some proprietary app that only works on Windows or Mac. Sure, if you're a programmer then you have access to everything you need on Fedora, but we are the least interesting group for the desktop, we are all power users and not the segment that matters.

But Linux is being used in those professional environments in some capacity.

"More recently, Linux has also been used on the workstations used by animators for drawing and modeling their creations, as the leading producers of animation software have tailored their applications to run on Linux." [1]

[2] is a demo video of Pixar's use of linux for animation and rendering.

[1] https://www.nytimes.com/2002/06/18/business/technology-disne...

[2] https://www.gamingonlinux.com/2016/09/pixar-film-production-...

[3] https://renderman.pixar.com/resources/RenderMan_20/installat...

Ah, you are too optimistic about the desktop in general. Landlines and desktops failed in the developing world first. It is contracting back to workstation users of old (STEM academia, IT, graphics) and maybe Adobe will do their hold out again like refusing to properly support windows when Mac was in the hole but they should get pretty desperate as the gateway platforms to their products become unwanted by the general population.

Adobe and Serif won't be around forever. The list of reasons why NOT to be on Linux in some form has been, and continues to, shrink as old proprietary software gives way to the new. While it's true that industry software is often restrictive when it comes to OS requirements and Linux is often not supported, I think we are seeing more and more platform-agnostic software especially in the for of web applications.