It's not just the features, but also the UX itself.

GIMP feels clunky and the UI is not as good. I haven't tried out the Photoshop mod. Apparently it matches all the keyboard shortcuts.

Many who tried to switch are complaining about how unintuitive it is. I know you can just try to get used to the different workflows, but unless the UX issues are addressed you won't see professionals making the switch.

Blender managed to completely overhaul their UI and it's now being used to create Oscar winning animated feature films.

I used Photoshop in the past and I think the UX complains are overly exaggerated and mostly come down to resistance to change. Most of the complains come from people who never used Gimp or only tried it for a couple of tried minutes. These people have lost every right to complain about windows really.

Because the same thing happens to me when I am asked to do anything in Microsoft Excel. I am using MS Office so infrequently that it is super unintuitive for me. It takes me less time to convert the file and edit it in libreoffice then convert it back to xlsx than using Excel.