The question of consent for being born is anti-natalist nonsense. Children cannot exercise their self ownership just like someone in a coma can’t. Nothing follows from that, especially any notion that this somehow justifies being ruled by the state.
Analogies for the state as a parent are absurd. And the anarchist claim is not that we can abolish the state, it’s that it is deeply immoral. Just like child abuse is immoral and likely will never be exterminated, as it should be.