In general, its better to teach people things before they need to know it so that theyre prepared by the time they need to know it rather than having to guess the first time around.
This is absolutely right.
Think about the concept of sex like swimming.
Abstinence only "education" is like you going to a swimming class and being told the best way to not drown is to not get in the water.
Waiting until puberty can be like jumping in the water, flailing around, and then having the instructor tell you what stretches you want to perform before getting into the water.
And yes, children will absolutely try to figure things out. With or without their parents help. How many of us discovered a dirty magazine or a dirty movie somewhere in our parent house? Children are sneaky.
It's better to have them know about the things they need to know before it becomes relevant. There is a fine line between "later" and "too late". Especially for those early bloomers.
Sure it's better to know ahead of time but the age of 4 is not necessary at all ---
You crawled and bled all the way but you were the only one... That was tearing your soul apart, you finally find yourself