I can understand the confusion, dw, but this was drawn before ai really got good at replicating smaller details (which is still struggles with today if you dont look closely). I looked closely at the rendering and line art and can say with some confidence that this was drawn by someone who REALLY knows how to render, wanted to pump out something REALLY quick, and was REALLY horny.
The line art is more akin to a cleaned up sketch, and the rendering, while looking Eerily Perfect at first, upon closer inspection you can see all the techniques they used to achieve that effect since it's still done a bit messily. Overall just an incredible authentic artist who knows what they're doing, powered by horny

Feels ai generated but honestly 10/10