Fujimoto doesn't use tropes about loneliness and abuse to make Denji sympethetic. He makes Denji sympathetic in order to say things about alienation, abuse, control, etc.

Hell yeah they get off too drawing the best landscapes

Any good art is the author's barely disguised fetish. If it's not it's probably corporate plot slop.

And fetishes are not just what other think of sexual. Real wierdos have fetishes that people might not even think of as a fetish.