People always retroactively justify anything they see as convenient and uncontroversial, stick to “everyone's opinion” (which does not exist, and is the product of their own projections).

One needs education to explain that, for example, hentai manga has little to do with realism, that character drawing styles have a long history that is only partially intertwined with lolicon wave started in the early 1980s (and that they even cross-pollinated with female-oriented manga along the way), or that the strict indecency ban (again, thanks to US) had created it in the first place (so little girls were actually used to portray proverbial 900 year old vampiresses because you could not draw those vampiresses that way).

Then we can see that any kind of image, even highly realistic, even photographs, is a deliberate set of choices made by the author, not a 1:1 copy of of “reality”. Then we can switch to the viewer side, and study how the contents of people's head define what they see, and how they react.

Here's a party trick. Japanese entertainment industry still produces a significant amount of media with young women in bikini. Weekly Young Magazine (one of the biggest manga periodicals) keeps placing idols on the front cover to this day. Ask someone about it, and listen to the expected comments about “questionable”, “seedy”, and “exploitative” nature of those (which are obviously true to a large extent). Then compare that to Western media products, global pop stars and such, and enjoy the excuses about it being completely different, “suitable for the whole family”, and “playing by the rules”.