GIMP does not even have a circle tool, and I don't think working around pointless limitations like that counts as "learning the interface."
The commenter above you used the software for 15+ years and specifically cited that lack of feature parity is the only criticism keeping them on CC. I have used both as well and do not follow your opinion about Photoshop, maybe because I never used those old school design tools. To me it looks like an Adobe UI.
Overall I just don't understand how you read the comments above and determined the solution is to learn the interface - honestly, the most tired and uninformed defense of GIMP there is. Especially when your primary criticism of Photoshop was... The interface. I guess the argument could be made you eventually get used to working around inexplicable deficiencies like above, but switching to GIMP is not possible if you need the features only included in Photoshop. There's not some random cosmic reason Blender and Inkscape are considered healthy competitors in their respective domains but not GIMP.