This should be helpful for people that learned Photoshop in the past (for work or in school). From what I understand, a lot of the friction with GIMP is the workflow differences, and potentially unintuitive UI/UX choices.
tldr: recovering Adobe Photoshop user shows you features in the very free and very open source gnu image manipulation program :D
my relevant GIMP config files: https://github.com/BreadOnPenguins/dots/tree/master/.config/GIMP/3.0
GIMP documentation: https://www.gimp.org/docs/
The same with Darktable and Lightroom.
Darktable is more powerful (a few thinhs missing though, like panos) but it’s UI is way different and super complex.
If you haven’t already, give RawTherapee a try. I can’t compare it to Lightroom, but I find it a lot easier to use than Darktable.