This is good news. There are a lot of great FOSS alternatives on Linux, but raster editing is one of the last few blind spots, I've found.
- Krita is designed more for painting,
- MyPaint also seems designed more for digital artwork (and, perhaps just in my experience, but it also seemed rather unstable and kept crashing)
- KolourPaint is very barebones (seems to be much more a replacement to MS Paint than anything else, so can't really blame it for that)
- Inkscape is a vector editor. 'Nuff said.
- Pinta is the closest to Paint.\NET you're gonna get on Linux, except it's based on before the latter went closed-source (bastard...) and as such it's not as feature-complete as Paint.\NET is.
GIMP, meanwhile, doesn't even have nondestructive editing and also can't draw basic shapes (like squares, cylinders, etc.), can't seemingly rotate layers without opening the [floating RMB menu] > Layer > Transform > Arbitrary Rotation dialog window, and good GOD the floating menus can go fuck themselves. How I hate the floating menus. Did I mention the floating menus suck? Not sure if I mentioned that.
Anyway, this switch to 3.0 is really needed and I'm genuinely excited to see the changes it brings, to the UI and the UX in particular.
Just a shame that they're switching over to GTK3 when most other developers seem to be transitioning to GTK4.

Hey no worries friend! I'm here on that bench with ya!
The Egg Prime Directive is a good policy in most cases!