I've never understood the people that do this in a world where there are professionals making ludicrously high quality productions using better models...
nah most of them are using SFM, which runs on a game engine. Meaning game quality models. In fact it's pretty likely anyone making 3D chun li content uses the same model, as a lot of the professionals focus on animation and using models made by others, and a lot of those models are based on game rips.
This was a sticking point for getting Judgement a PC port. The actor didn't want it going to PC because he and his agency knew that people could just rip out the assets, which look exactly like him, and generate new works with them.
I still disagree with that decision, like he's a public figure regardless of what happens he's producing work and putting his name to it. If people really wanted to, they'd find a way to use his likeness, PC port or not.
They don't want ludicrously high quality productions using better models. They want Chun-Li. And under their control.
This isn't my thing, but I mean, you like what you like. It's like asking why anyone reads porn when video is available. They just don't scratch the same itch, and you like what you like.