The first thing to remember is that Krita is a 2D paint application while other programs such as Photoshop are designed for image manipulation. This means that the other programs may have more features than Krita in general but Krita has tools that are relevant to digital painting.
The tools are designed for concept art, creating comics, and textures. If you use a feature that isn't listed, make a quick video tutorial and let us know. We'll put it up to share with everyone!