At this point everyone should be looking at Krita instead of GIMP. Krita has a much slicker UI, more features, and similar keyboard shortcuts to photo$hop.

Aside from the common complaint of its odd UI decisions, the thing that got me about GIMP last I tried it was how rough around the edges it is on macOS. It seemed very confused about my dual monitor setup for example with modals doggedly showing up in the top left corner of one of the two monitors no matter which monitor the main window was placed on.

I wish somebody could implement a Photoshop UI for GIMP. I am using GIMP as my main photo editor but there is a lot of UI pain. A lot of it. Many things are counterintuitive.

I vaguely remember a fork that at least turned it into a more traditional model app instead of dozen small windows floating on the desktop. That certainly helped.

Edit: Aha! Found it. https://en.wikipedia.org/wiki/GIMPshop Abandoned in 2007 though.

It has had a single window mode since Gimp 2.8 was released in 2002. Unfortunately it's not the upstream default, but a lot of Linux distros set it that way anyway.

https://docs.gimp.org/2.8/en/gimp-concepts-main-windows.html

There is this project that might help you:

https://github.com/Diolinux/PhotoGIMP