I think the mental state is key. Pogacar literally had nothing to lose. He knew where he was at on the TT bike and "all" he had to do was go full gas on the climb. Meanwhile, Rog watched Pog blow out of the start house and was getting time checks leading up to the climb that showed him losing more and more time. Also, Pog had beaten Rog in their national TT, and that may have already been weighing on Rog from the start
One guy with nothing to lose versus the other guy who is watching it slip away...