GIMP is alright. Mostly I stick to it because Krita's dependency on QT means it looks and works differently from everything else in my GNOME environment.

I'm not an artist, I just need the occasional hack job or screenshot annotation.

I loved the simple programs (this love stems from all the way back to MacPaint v1.0) and MS Paint has largely been ok for me apart from its lack of png support and only 90° rotations.

On Linux, Pinta has been fantastic but these last few years it got increasingly more crashy, to the point where it will now consistently crash within 10 seconds or two clicks, regardless of Linux distro / laptop/pc / version of Pinta. (insert "whyyyyy" meme here)

I've tried Krita, but it's simply too much. Don't even want to try installing Gimp. I am sad.

Image is a broad word. I would say in order of usage per year it would be Darktable, Inkscape, Hugin, GIMP, Krita… but these obviously serve different purposes.