from your post, it appears that you only see this as a "How Things Work" kind of education...which is the "Sex" part...but do you see the "Sexuality" part? IMO, that's even more important, because it puts sex acts into the context of 'committed relationships' and not just getting personal pleasure.
When kids are taught as much or more about 'Sexuality' IMO the likelihood of unwanted pregnancies, or STDs goes way down...it also makes for more committed relationships, which adults like ourselves recognize as the enduring part of marriages...you can see where I'm gong here. That type of education can start much earlier than the anatomy and baby making lessons...right?...in fact, if you read all the materials I've provided, the rationales for each program express that objective, and explain why countries/states that employ "Sexuality" education experience the benefits documented.
It's the "Sexuality" and "Relationship"...as well as "Mutual Respect" parts that need to be embedded in children's minds, more that the "How To"...and that takes real skill as well as commitment on the part of teachers, specialists and outside guests working together with parents.
Note: my wife and I joined a group of other couples in our Diocese to get trained and then lead sessions for Engaged Couples...and sexual "Relationships" were an essential part of that program. Let me tell you that virtually all of the participant couples were in need, to one degree or another, of those insights...just think of all the couples who don't get such 'training', and the statistics that show ~50% of U.S. marriages end in divorce., btw, we got into this because I remembered a couple who came to ND during my senior year and spoke only to seniors in Washington Hall...there were no limits to the questions that could be asked...and they shared their personal lives with all those students...questions like "How often do you have sex?" were asked...and they answered honestly...but also sharing why that wasn't a concern at all...because of the focus on their "Relationship" more than pure pleasure. I could go on, but I trust you can understand what I'm getting at.
I'm not saying this is easy, or that everyone would do a perfect job, but these topics are not being addressed early enough and wide enough...ignoring this aspect of our children's development is negligent and cheats them out of a better life...never mind the societal penalty.