If you think that this is how it works, then you're delusional. They're still young players, they've had large team problems, that often affects performance heavily. Teams have ups and downs, and with that, individuals have ups and downs.
There are a million examples of this happening, but take GuardiaN as one. He was an old player, who had had one of the worst performance dips in a top player in a struggling NaVi, yet after joining FaZe, a top, proper team, he completely revitalized his game and went from a bot back to being one of the best players in the world.