I am curious which previous or even subsequent performance by Vingegaard gives you the impression Pog at his best could not follow Vingegaard on Granon?Pogi would lose the tour anyways. He would never be able at his best to follow Vingegaard at granon. Probably at his best, without mistakes he would lose 45 s/1 min.
But then, on hautacam and the ITT, Vingegaard proved that he was the strongest. The strongest team and the strongest rider won. I don't but that narrative of "pogi lost the tour because of his mistakes", and i am a big fan of pogacar.
On Granon the damage was done responding to Roglic's attacks and blowing up. Then Pog attacked continually all the way to Paris expending huge energy with an inferior team. Don't underestimate the roll the likes of WvA played after Roglic withdrew. Plus, as mentioned by Shadow, there were other factors against Pog which explain Hautacam and the ITT.