SSDR, not all of my (3D) graphics work is diagrams -- the one you chose is a rendered 3D landscape (in the background), from the 'labor credits framework' diagram, and then put through filters (GIMP + G'MIC), for the 'painterly' look that you see.
Artistic works, and other kinds of artistic expressivity, don't *have* to be useful in the utilitarian sense -- in fact, I have a *diagram* that shows this, with 'art' and 'literature' being more-socially-useless, while social science and (hard) science are more socially *useful*:
Humanities-Technology Chart 2.0
This is *philosophical* terrain you've stumbled into -- should humankind restrict itself to only socially-useful kinds of activities, like those of building buildings and making technological progress, while never really *enjoying* the fruits of those endeavors, instead just looping back into producing *more tools, goods, and services* -- ?
(In that case everyone would be doing 'useful' / utilitarian things, incessantly, but then no one could ever relax and actually personally *use* those things since that would be *useless* activity.)