The GIMP just doesn't manage to hit the productivity nexus for anything constructive. Simple things are annoying, complex things are infuriating, vector support sucks, mixed vector/raster mode with layer styles doesn't really exist, layer management is barely reaching parity with where Photoshop was 20 years ago, and overall it has consistently left me frustrated and unable to get into the flow - you have to work around its deficits rather than being able to compose its features in novel ways.
Being able to maintain several 'versions' of the same image just by showing/hiding layer groups while still being able to edit & adjust things fluidly is a crucial feature in Photoshop, with GIMP you end up making copies of copies of copies and if anything needs adjusting or re-composing in the source layers you'll have to go back and perform the same sequence of steps and discard most if not all of the layers you made.
Yes, you have 'make selection from curve' and other tricks in GIMP to maintain your masks as vector data, but it's an awful lot of trouble and is a laborious N step manual process after every change.
Layer styles were basically CSS, for complex raster data, and it works beautifully.
Literally every modern graphics workflow.
The copy/paste flow in particular still trips me up.
Pasting creates a "floating layer". A "floating layer" usually needs to either be "anchored" (merged down into the layer below) or converted to a "new layer". In the meantime, for example:
* If the move tool is selected and the "floating layer" is clicked, the "floating layer" is draggable on that click. * If the move tool is selected and the canvas is clicked outside of the "floating layer", the "floating layer" is anchored and undraggable on that click. * If the unified transform tool is selected and the canvas is clicked anywhere, the transform frame is activated for the "floating layer" and it is rotatable on that click. * If the erase tool is selected and the canvas is clicked anywhere, nothing happens, except that the UI flashes. * If the paintbrush tool is selected and the "floating layer" is clicked anywhere, it "paints" – though pixels are only affected within the bounds of the "floating layer", as that's just how things work in GIMP.
I'm sure there are perfectly sane reasons that things ended up like this, but the result feels weird to me. I don't really want to have to think about "anchoring" a "floating layer" after pasting it, much less think about what the UI is capable/incapable of doing while there's a "floating layer".
I've since moved on to Krita. It feels far less weird.