Over at the Emacs subreddit, ismbks asks about drawing tools for Emacs. If you’re like me, the only thing that comes to mind is artist-mode with possible export through ditaa. That combination has always met my needs but it is pretty rudimentary and mostly confined to block diagrams.
The comments have some other solutions. On really nice example is AKIYAMA Kouhei’s Emacs Easy Draw. It’s very interactive and has nice line drawing capabilities. Take a look at the demo on its GitHub page to get an idea of what it can do.
Another commenter recommends PlantUML, which is good for flow diagrams and fancy block diagrams. It’s a markup application rather than interactive if you prefer that way of working.
Of course, all these applications are meant for engineers needing to draw engineering diagrams and not for artists who want to do serious digital art. Emacs is probably never going to support that sort of thing and why should it? After all, there are applications specialized for that and it’s hard to imagine a need for doing it from within Emacs.