GIMP for example is nowhere near feature parity with Photoshop

Yeah. That’s exactly my point…maybe I wasn’t clear.

The problem is that no one specific FOSS tool has feature parity. To get the same abilities as Photoshop, you have to use a workflow that is a combination of GIMP, Inkscape, Krita and Scribus instead of having it in the one package, which is why Adobe is the industry standard.