I use Windows. It does what it needs to do, and while I haven’t upgraded past 10, it’s not complained about much.
At home I switch between Fedora and Windows, but at work I use OSX because using Linux at work gets you a shitty laptop instead of a MBP. I work for a big tech company, with the Windows and Mac user communities being pretty much the same size. What I’ve noticed is that Windows is fairly tolerable, and often has few issues that don’t need IT intervention. The MacOS community, while often being more technical because it’s used by tech workers, has a lot more issues than any other. Major OS updates are events that take months of planning because it’s guaranteed that thousands of people will essentially brick their laptops trying to just do a standard upgrade. Everything seems to break all the time, which is mad when you consider that Apple is a trillion dollar company with one hardware line. Windows and Linux support many hardware lines.
Ultimately, you know what you’re getting with each choice. All I care about is that my OS does what it intends to do.
Sadly, I don’t see Gimp ever competing with Photoshop. It’s not necessarily a feature parity thing, nor is it a mind share thing. It’s as you’ve said - it’s not built by creatives to be the best possible tool for many types of design.
It’s truly a shame, because for years Adobe slept on different aspects of digital design, and there was a true opportunity to build a Linux-first tool that made things like Web Design so much simpler. It’s an unpopular opinion, but Linux window managers have always lacked creative input. There has always either been a design-by-commitee, or a design-by-engineer feel - and this is reflected in how poor Gimp and design tools are in the Linux space.
In reality, Linux could have the best photo editing and design-specific tooling, but sadly the tooling either lacks a creative touch, or lacks features that are truly needed to be competitive.