He has been grinding on yoru and raze lately and has definitely got better.
His problem was that he played jett in almost every ranked, champions taught him a lesson for sure.
yeah before he was just insta locking jett no matter what but now on maps like split, icebox, and bind he is playing instalocking raze and not jett, looks like he actually wants to improve.
I'm not saying you can determine who is good and who isn't, just the level of comfortability a player has on an agent. What better way to practice it than in game right?