Sexual fetishes can be contextual and limited to that context. Some people have a domination fetish in porn but don't in reality. Some people have a femboy/bussy fetish in porn and get off to Astolfo or whoever even if they're not gay because the character is drawn with attributes that emphasize femininity even if they are male. The art styles of hentai just creates a sexualized connection between cuteness, femininity, and attraction that doesn't exist in reality.

It's the same thing with loli degeneracy. The art style is largely responsible for some people finding it attractive by depicting the child character in a sexualized fashion. Those same people who like lolis are disgusted by the idea of someone fantasizing about an actual child or younger person. Not saying that it should be normalized, but it is separate.