It isn't a ridiculous statement, he is simply a ridiculous player.
Coaches don't just make you great unless you are naturally great. Deferring this discussion to coaching is taking a lot from Mendes natural talent. Great players do great things under any coach, and Mendes was always like that.
Coaches job is to make a system that gets the best out of the talents he has, which both Flick and Lucho consistently do.
Well it goes without saying he's talented I and everyone else have said that.
But coaches improve players and development tactical systems to highlight their strengths and minimize their weaknesses.
We see it with pep, we've seen it with lucho, not so much with flick from a development of a player prospective, but he does put in system's to make attacking players over produce.
To say he was THIS good 2 years ago, bar injuries is ridiculous and wrong.
Dembele didn't improve his decision making with age, he improved it because he had a coach that thought him how to make better decisions in certain situations and his talent did the rest.