>>511249942 (OP)Girls on average become sexually attractive once they begin puberty, and they reach their peak attractiveness roughly at 14, which is shortly after the end of puberty.
The reason why there is a longstanding fascination with 10-12 year old girls is because this phase of youth is so short and therefore so rare.
If you take a pool of women, aged 10-30, all the women aged 14-30 look roughly the same: they have all developed secondary sexual characteristics and finished growing. But the girls going through puberty display some very specific characteristic signs which are ephemeral and therefore rare. And because they are rare they are more highly valued by a subset of men.
There is also another psychological reason: the pubescent girl shows a glimpse of what might be. This potential is enticing. With the adult female you have is what you get, but with the hebe you are titillated, teased by what might be, by what she might become.
Attraction to pre-pubsecent girls is mostly a psy-op, and constitutes a fetish not all that different from other weird fetishes you see in the population.