If this comment isn’t the perfect distillation of the frustration people have with GIMP, I don’t know what is.
OP makes a very even-handed, consciencious treatise to gather more info about alternatives to GIMP based on the UX issues they themselves have been struggling with and which are commonly recognized throughout the community, with at least one example, while acknowledging how incredible and powerful an undertaking a piece of software GIMP definitely is, and…
… The same cookie cutter response on every single GIMP discussion since 1998: “IT IS VERY POWERFUL. WHAT FEATURE IS IT MISSING?”
Similar to GIMP itself: You’re not wrong you’re just… Not being anywhere near as helpful as you could be.