Of course such an effort most likeky would need to be a paid effort fulltime rather than volunteerr work.
It always felt sad to me it never reached the usablility/familiarity that Blender has.
Longterm, we have a roadmap item for an Extensions platform: https://developer.gimp.org/core/roadmap/#extensions
So basically, you could download plug-ins, themes, shortcut presets, etc, directly into GIMP. We have a lot of pieces done - we just need someone to focus on it to finish.
The differences are pretty substantial sometimes don’t get me wrong, but your previous experience usually carries over in more ways than it doesn’t and you’re able to get up and running with like…80% of proficiency you had on your preferred program after a month I’d say.
GIMP isn’t quite that smooth of a transition and you can feel it. I don’t think it’s necessarily a fault or something they should spend resources addressing, but it is noticeable