I was one of those people who switched during the early Ubuntu days of 2006/2007.
First heard about it and gave it a try in 1995 when a friend told me about it in college. I was/am a graphics artist so it wasn't an option then. But I knew then that it probably would eventually get there and windows would keep getting more evil and that I would switch. So I started switching from proprietary software solutions to open source whenever possible so that it would be easier to do when the day arrived.
So... in 2006 I was hearing a lot of talk about linux finally being easier to use and setup with a lot of gui functionality. Which is required for graphics work. Although, I had adobe at work and was there most of the week, so I didn't really care anymore about having that at home. And the stuff I played around with was blender and the like.
I was also getting out of the habit of gaming. I had been really into FPS. Mainly the half-life mod "Day of Defeat" where I was doing the clam competition thing. But I burnt out on it and didn't really care as much. But I did dual boot for a while with gaming in mind. It was about a year later when I realized that I hadn't booted into Windows for several months (and I needed the hard drive space) that I scrubbed it.
So here I am.
I still use Ubuntu variations mostly. Although I intend on switching to Devuan. I've been experimenting with it on a laptop to get it just the way I want it before switching my desktops. I'm still struggling with btrfs snapshots. I thought I had it recently, then I broke it somehow. I'm still not entirely clear what the whole snapshot thing is doing. But I look forward to getting there soon. I hope to make this my final linux setup for the next decade at least.
I hear ya. I'm a print designer and the biggest hole is scribus. It is impressive for how good it is in the last few years, but is no where close to where I need it to be for pro work compared to indesign.
But, I think Krita is definitely good enough to do what I need photoshop for... and Krita is better in some ways. Like for illustration work. Krita is better than GIMP for my uses because it has the strong color model functionality that GIMP doesn't have. Mostly that would be the CMYK functionality. GIMP only exports to CMYK. You can't work directly in it. You need that for print design.
Interestingly, the biggest problem is the whole "using Photoshop for over 20 years" (30 for me) thing.
After several years so much of what we do with these programs becomes second nature and we don't have to think about it. Even if the other program is better, it takes a lot to get to that level with a new program. I'm trying to use Krita more and more and I still feel like I am no where close to that goal. albeit... somewhat closer..
While GIMP does have a clunky interface, I think part of that is that we just aren't as familiar with it as the program we have been using for decades.
I don't know what you use gimp for, but Krita might be worth a shot. Although I think if you only work in RGB and only do "photo shop" kind of tasks, GIMP may still be better.