I am not quite from Slovenia but I know the region a little bit. Believe me, it is not like in France for example where kids are coached for a very young age and everything is optimizes. It can happen that a talented boy gets selected and that boy is not training like a maniac. Heck, in the country where I come from even untalented and non training boys get selected

.
The likelihood of anyone achieving what Pogacar is doing simply by training harder and better is so infinitesimally slim as to be non existent.
Any even rudimentary analysis of cycling history will put into context what he is doing is unprecedented in modern times, post 1980. Cycling at the highest level is such an extreme sport, with incredible demands on the human body. Any cyclist who rides for world tour teams is a world class athlete, dedicating their life to the sport. The relative differences between them are marginal to say the least. For the very very elite, the differences are even smaller, and any legitimate marginal gain that can be eked out of a new supplement, training method, sleep regime, whatever, is merely going to deliver a sliver of a difference if at all. Likewise, the human body operating at this level is naturally much more vulnerable to injury and illness. Fatigue wears down the immune system and muscles and tendons put under so much workload are at a higher risk of developing injuries, as well as simply breaking down from fatigue. That is why cyclists need to train and recuperate in cycles, which is why they work with their team to target specific blocks of races that suit their specific skill sets. To do otherwise would not only be unhealthy for the rider, it would not maximise the chance of winning or accomplishing the best achievable results. It would be utterly stupid.
So why, then, do the laws of nature not seem to apply to Mr Pogacar? In answering this you will find the truth.