Correct - GIMP is (largely) focused on photo editing, while Krita is (largely) focused on digital painting. Although GIMP/Photoshop definitely support a digital painting workflow with custom brushes and the like - it's just not the primary focus.

I would not say so. Gimp is (arguably) a very long evolution of an mspaint that copyied many tools and workflow from a Photoshop, Krita is an attempt to re-implement Photoshop from scratch.

I wouldn't say Krita is not suitable for general editing, because Photoshop is also dual purpose tool - it is an industry standard both for digital artists and general photo manipulation.

They have different focus, but both are raster editors. They do compete with each other.