Really? To give just one example, if I press cmd-T in PS, I go into an editing mode where I can translate, rotate, and scale a layer with intuitive, contextual mouse controls for each. With GIMP it's broken up into separate commands. I didn't spend so much time with it, but with PS things got guessable very quickly, where with GIMP it felt like the features are just stuffed in there wherever they can fit.
That proves the point, you simply don't know how to use Gimp yet. It is called "Unified Transform", available on the default toolbar or by pressing "shift-t". So the difference is literally pressing shift instead of control, a trivial difference by any standard, and reconfigurable as well.
Yes it does prove the point. So if I look at these docs[0], this tool, not only does it do translate/rotate/scale, which are the most fundamental image transformations in 2D editing, but it also does shearing and perspective transformations which are rarely used by comparison. This tool was clearly designed from an implementation-driven perspective (just put all the affine transformations in one place) rather than a UX driven perspective (no designer places these tools together conceptually).
On top of that, this tool still sits along side other single purpose tools for scaling and rotating, which are the first results if you search "how to rotate in GIMP", so why should I even expect this tool to exist?
This is not intuitive UX which is "trivially different" to PS, this is a mess which can only be learned through laborious trial and error, or reading the documentation like a book.
Many open source projects such as Gimp have a serious UX problem. Software engineers are great at delivering efficient systems. In terms of usability they’re arrogant and inflexible. They’re two different skills and I wish project maintainers understood that.