Because they never played as advanced as him in that moment. However composure on the ball and bringing it out from the backline to the frontline is what they're known for.
His base skills can be used anywhere in midfield, they wouldn't be wasted in front of the defence. That's just dumb logic. What he did in that game is something truly special but he won't need to do that in his football career.
However the rest, calmness on the ball and linking up play, that's his game
He was actually playing as a 6 when he did that, Casemiro had been subbed off. You saw a young man take the game by the scruff of the neck and win it. There’s no dumb logic in wanting the nurture that further. I’m not saying I expect him to do it all the time but the capability to commit and beat men is obviously more impactful a bit higher up the pitch. I think it’s where he prefers to be too.
Ultimately where he plays depends on how you want to construct a midfield because as you said, he can play anywhere really. Personally I don’t want my 6 to be a deep lying playmaker. The burden on them is so heavy defensively, especially in England. To expect them to protect on transitions and dictate the tempo is too much I think. It’s better to have a specialist 6 who can cover a lot of ground and is quick, in the modern game one counter attack can flip the entire game.
I’ve always preferred the construction of a physical 6 breaking up play & keeping it simple, having a 8 to connect and dictate tempo and a 10 to provide the creative thrust. Of course you can have 2 sitting, a bit like Carrick and Scholes, which changes the equation a tad.
