I worked in prepress, so pretty good an Photoshop, and vastly prefer GIMP. The problems with GIMP are technical, there are some necessary things for some jobs that it simply hasn't been able to do, but I'm seeing a lot of work being done on them.

The problem with GIMP in industry is 1) that .psd is a standard, and 2) that Photoshop has a bad UI that takes a lot of work to understand well enough to do the very fine work most people are doing with it. Nobody would want to start over even if the consensus was that GIMP was better than Photoshop; Photoshop would still be good enough.

Hopefully Adobe will be user-hostile enough to lose a bunch of people to Affinity, and a bunch of people on Affinity will weaken Adobe standards in industry generally. GIMP could sneak in on the back of that.

GIMP is Free Software, it only gains features, never loses them. In the long term, there's no way anyone else can compete.