Let's be real though, it also heavily depends on the country. Take a country like Kenya, poor. That means that 1. athletes have more motivation to dope, so to win more, so to get money, and 2. officials have more incentive to get bribed to manipulate testing. Ruth Jebet, the Kenyan starting for Bahrain at last year's world championship ran a time of ca. 09:30 in the 3000m steeplechase. A year later she runs the second fastest ever time of a woman, only behind a very clear Russian dope cheat, and over half a minute faster than her time last year. Yea, she trained so hard she managed to go half a minute faster
So the point is, certain countries have much stricter and much better testing in place than others, too. There need to be some very drastic changes in sporting. And yes, that would include starting to test young athletes. If you are good and do well at youth competitions, get tested. If you suddenly appear out of nowhere with amazing times/distances/feats, get tested. And there must be much more severe punishments, otherwise what's the deterrent.