Check his seasons 2015-2017. Nothing special. He won the Giro di Lunigiana in 2016 against a bunch of nobodies. He won the 'biggest race' (without a single stage win) after he signed for Gianetti, comparable to Torres who set a record on the Finestre as an 18-year old... after he signed for Gianetti.Riders ride the same races for different reasons. They did that back then as well.
He has had bad days, as been stated. Other great riders have been beaten him a few times. Right now he is at his very peak. It is not strange that a rider of his talent is winning races. He is on top of his game at the moment and winning a lot of big races.
Your claim is also wrong. He was good as a junior, progressed in U23s and won the biggest race. Already did well in pro races, before going pro were he started to win early on.
Do you want to see the results of talented young riders? Check Evenepoel, Seixas and Van der Poel.