> Niemann, as black, equalized reasonably early on and then had a consistent lead against Magnus the entire game. Magnus did make mistakes in the game, but only after a near-perfect grind for 27 moves.

Of course he played near-perfectly for 27 moves. That's what it means to be a 2700 (or even a 2500, if you think his recent ratings growth is the product of cheating). Virtually any high-level game will look like that - the players playing mostly perfectly, with on average one or two significant mistakes, but sometimes not even that.