The most difficult lifts to perform in all of lifting are the clean & jerk and the snatch. Seeing the world’s best at c&j (clean and jerk) doing 575lbs/260kg+ and snatch doing close to 500lbs/226kgs are such impressive feats to witness. If you think about it though, most of those people that are close to those weights have been training Olympic Weightlifting since they were 5 years old or younger. So they have upwards of 20+ years experience with it.
Now you don’t necessarily need to have 20 plus years of experience in it to be able to perform these lifts competently. But you do need more than the 4 years of the typical high school training in it to be good at it. By the time most high school students are seniors they will have usually terrible form trying to force more and more weight up.
To try and fix this, instead of trying to get kids doing heavy weight right away with terrible form, there should be about a 2 year, at least, time frame of learning the foundations of Olympic lifting.
I would say the most optimal time to start learning how to do weightlifting would be sometime around 8-10 years old. At this time children still have the natural flexibility to perform all of the actions and are more keen to learning new concepts. If kids can get upwards of 4 years of experience with weightlifting before they hit puberty they will be more than ready to start lifting heavy amounts of weight, and maybe they can become world competitors too.