You're making the assumption that what is provided by schools, other institutions, or the state is of inherently superior quality to what would be provided by parents. Or what is best for the child.
This is questionable thinking and poor reasoning. It's a dangerous assumption as well.
During my time as a young woman, schools taught the rape equivalent of "stranger danger" rather than the realities of rape statistics, they slut shamed, the put the entirety of sexual conduct responsibility onto girls. Churches preached purity which left many young women incapable of enjoying sex and many young men groomed into being predators, they also dumped all sexual responsibility into the laps of women. The state, under a campaign of ending teenage pregnancy pushed birth control onto all still developing young women regardless of the long term consequences to their health. I'll remind you that back then, birth control was a lot harsher than the options available today and there weren't as many options.
What we didn't get was anything useful, practical, appropriate, or developed with our general well being in mind instead of, say, the convenience and desires of men.
Sexual education offered by state and religious institutions are inherently going to be centered around shame, ignorance and control because that's what these bodies are for...to control the population. That's their agenda and why they exist.
A certain amount of that is okay, it helps us all get along l, minimizes conflict, and establishes basic rules and things.
But sex is such an intrinsic, important, and individual expressive part of our lives, I think we need to be very prudent and cautious over the level of say we want to hand over to institutions about our private and sexual lives.
I got a decent enough sexual education from my family. I get that a lot of kids don't.
But I have two questions here.
1. If parents did not have institutions enacting effort here, would more of them step up to that responsibility? In other words, were fewer of them abdicate that responsibility to the state because it's embarrassing or hard or whatever?
I believe so.
2) If I had gotten zero sexual education from my family, and all I had gotten was the institutional offerings, would I have been better off than the nothing in that situation?
Gonna say no. The fact is, that without the often contradictory (to the state) things I learned from my family, I would be as angry many women in my age cohort are today. I would had a worse life. I woulr have been raped likely multiple times (zero doubt here). I would feel like I had been set up for a bitter, painful, lonely life.
That's what the state and religious institutions have provided to women.
Obviously, I can't speak for men, but I'd guess there's some hard feelings there too, regardless of whether they are cognizant of the sources.