Sacred Haven of Debauchery

>an adult wants to have sex with a child
>the child agrees
>despite both parties being willing, we, as a society, have determined that due to the potential consequences for the child and the fact that the child does not have the necessary experience, knowledge, and/or a sufficiently developed brain to make such a decision for themselves, even though they have a consciousness that says "yes," their answer always defaults to "no" because they lack the ability to make an informed decision.
>this is accepted by most societies, and you will be called a freak for questioning it.
so far, so good.

>an adult wants to have a child
>the child cannot agree because it does not yet exist (neutral position).
>despite one party being willing and the other not having a stance, we, as a society, have determined that the potential consequences of this and what to do with the child are entirely dependent on and subject to the decision of the adult, despite the child not being able to say "yes," both because they do not have a consciousness and because they lack the ability to make an informed decision.
>this is accepted by most societies, and you will be called a freak for questioning it.
this is where it stops making sense.

by definition, the decision to exist is a FAR bigger decision than the decision to have sex at a young age; in fact, it is the biggest decision there can be for a human being, since all subsequent decisions you make are derived from it. Yet, you cannot make such a decision informed (since learning information requires existence), nor can you argue that their brain is developed enough (since it does not exist). Isn't it, therefore, hypocritical to allow one but not the other?