>>6503067I find that looking back on a lot of doujins from the early 2000s and before, the vast majority of it features mediocre at best anatomy, with a lot of slop and inconsistency, getting worse the further back you go.
There is some very good art still, but a lot less of it. I think with time there was just far more and accessible resources for artists to grow and develop. Most doujin artists aren't excellent today either, but usually the anatomy looks decent and consistent.