When I was playing (about a decade ago) we made heavy use of static images. A few people drew their characters, others pulled images from online, and our DM would always flash an image of whatever boss we were about to encounter. These were all intended to be rough approximations, and were typically shared with deviations, e.g. "my character looks like this guy, but he uses a staff instead of a longsword, and he has a lot more hair!" My girlfriend plays with some artist friends, and they regularly doodle their character's escapades.

Art is nice. Customized art is nicer. Also, it's interesting that (as you note) it's far from universal. My group would likely have enjoyed using AI art for our campaigns, but my girlfriend's groups have completely rejected it.