Because schools would teach without biases? As in, they would teach about safe sex and contraceptive use as opposed to just abstinence (which has been proven ineffective. States which emphasize abstinence have the highest teen pregnancy rates in the country).

They also have better education regarding human biology and wouldn’t spread as much misinformation in compared to parents who are uneducated/misinformed with outdated facts.

This would also ensure that children with parents who are too uncomfortable to have “the talk” (mine were like this) still have the opportunity to learn about sex education with a trusted adult.