As I said, he put in the work, however a coach identified the problem and gave him a solutiong. To say coaches can have little to no bearing on a player's shooting is still a dumb take even if we walk back from it.
I guess we can agree to disagree on this. I'm being a bit hyperbolic, but I believe absolutely that coaches have little bearing on shooting. There's a reason that guys on the same team, with the same coaches shoot wildly different percentages across all levels of basketball. It isn't because they ignore some players.
It's great that they pointed this out, but it's kind of a throwaway analysis you could give to every player at every level and tell them to do the drill. It's about as common a problem in shooting as there is, and doing the drill a bunch is going to help every player.
And I know it's different, but this is also a guy that shot 40% from 3 as a freshman in college, and his first actual season was his best 3P% of his career.