Hi!
Krita is one of the best graphical software available for linux, its not a replacement for either GIMP, Inkscape or other programs that are already on the list.
Many people including me have used it on Windows also, that is the must-have program for creative art.
I need to check again how much of KDE is also installed when Krita is installed. MyPaint is included as an alternative.
Apt wants to add over 450 MB for Krita, but the Krita snap is just under 100 MB, and you get the just-released version 3. Can the Boutique install snaps yet? 
Yeah, a Krita snap in the Boutique isn’t a bad idea