>>52498671People don't actually care about that to the extend you're implying. When looking at the raw data most of the more human-like Pokemon don't get much NSFW material and/or lack high smash rates. Every Pokemon exclusive to the human-like group, for example, has subpar smash rates below 50%. On top of that smash or pass shows that Gardevoir doesn't dominate at all, it's almost identically tied to Lopunny and it's not far off from other Pokemon. You see this song and dance in places like r/pokeporn,
rule34.xxx and even Gelbooru when sorting by score, Gardevoir isn't dominating it's sharing the spotlight with Lopunny, Braixen/Delphox, the eeveelotuions, Zoroark and Lucario. So really, it's not about that, Pokemon don't represent human-adjacent creatures and people reception to this is to not care much about it.
Instead what really helped it become the face of feminine designs, much in the way Lucario is for masculine designs, is simply being there first. And in a way there's really nothing to dethrone since in the popular imagination it shares the same spot as Lucario, Lopunny and Vaporeon among the general public. Meowscarada will most likely join this group that forms the core of Pokemon attraction.