I tried gimp back then and a few years ago, it’s clunky, slow, and unintuitive. I haven’t tried krita and seems like the better tool than gimp. People use adobe mostly because of legacy and much more complete software and intergration(seamless export between their software like photoshop straght to premiere). Granted my last experience with adobe is almost two decade ago, so not sure how much changed.

Edit: i tried Inkscape as well a few years ago for vector drawing, it crash often and pretty laggy iirc. Not sure about now though.