My parents didn't really say anything about sex. Mom would have been the one if anyone, but was too shy to even talk about puberty. There were vague warnings, sharp exchanges when my sisters came home late. I think she mostly assumed school taught us the details we needed. She didn't get far in school and probably thought they educated us well.
4, or 5th grade had a fun puberty week, I recall a lot from that. Later sex ed was not lacking in information, but the delivery was horribly boring and of course, reproduction was a main focus--which felt irrelevant to me from early on. Later, I forged Mom's signature to get out, Mom might have found out. She probably also knew that I was absorbing EVERYTHING I could. Her magazines, my sisters', romance novels, encyclopedias, Clan of the Freaking Cave Bear in 4th grade, and eventually, we had the internet. And my friends were nerds and mostly didn't think much about sex until late in their teens and early 20s, so I didn't hear much of urban legends. Some friends learned a bit about sex from their parents, but I don't feel they were better off than me.
At 17, when I was still a virgin, I knew more than experienced acquaintances did. I've only had one sex partner since, never been accidentally pregnant, have caught no STDs. I think I'm doing well despite my family's "failure to communicate".
I doubt I will have children, but if I did, I think I would be a little more open than my parents. I would keep lots of good books around for naturally curious minds and maybe assign a somewhat older relative I trust to be their more "removed" go to for wisdom. I don't think it's wrong to not be able to talk to one's child about sexuality as easily as one discusses homework. But I think one must make an effort to understand where their child's development is, they should get to know their children. Which is probably easier said than done. Or maybe not. My mom at least was often home and always had a basic idea of what was going on with me. My parents probably didn't suspect some of my adventures, but I think they mostly knew me well. The leash was shortened when they thought it needed to be. Haha, and they gave my boyfriends mild interrogations.
I feel like I grew up with my own sort of sexuality. My parents didn't structure it for me. Because it was a taboo topic, sex retains a wickedness, but that's the way I like it.
Some of my beliefs relating to sexuality probably wouldn't sit well with my parents, but that's OK. It isn't their business.
The method my parents used is not a one-size-fits-all method. It would be disastrous for some. But not all.