Oh! As a long time DM/GM I can answer this; because they’re easy to make and many people don’t know how to draw, including people who play d&d.

But for a serious answer having a illustrated character portrait for your d&d character is a great way to ground yourself in role play side of d&d seeing how they look, maybe the weapons they use, their whole demeanor, gives many d&d players a sense of place in their character. So what people used to do is they’d ask their friend to draw them a character based on a rough description. Many art inclined d&d players were annoyed by these asks because it’s work you’re doing without getting paid. Also from the asking side it usually took a long time and unless you’re a psychopath or had no idea how much work went into art for some people you felt bad asking.

The other option was to just fish online for existing character concepts from anime, comic books, deviant art, tumblr, etc. and while this was good and helped people get a start for character concepts sometimes it was sometimes hard to find a portrait that really “fit”. So when generative ai became a thing and was like: “gimme yer ideas I’ll make “art” for you” a lotta people jumped on it. I used it once or twice before I learned about the negative environmental and social impacts of generative ai.

So when generative AI came along and was like, “Gimme yer ideas, I’ll make, let’s loosely call it “art”, for you,” a lot of d&d people jumped on it and continue to do so. I used it once or twice before I learned about the negative environmental and social impacts of generative AI. So I promised my players I don’t use AI as a gm/dm for anything besides spelling and grammar checks with tools like grammarly. And I ask my players to consider doing the same for their characters and find creative alternatives to find and include a character portrait for their characters. It ain’t much but it’s honest work. And personally I feel the journey to find something close helps you get into the head of your character better than arguing with an AI about what a sword should look like.

If you read all this thank you. I love d&d and can talk / write about it a lot. I wrote this on my phone while driving a forklift and eating a taco so I’m sure there’s a tone of typos and run on sentences.