This may only Be my own theory. But I always felt in the 90s, all those good AFC teams beat up on each other, such that when we got to the SB, we always got some well-rested and healthy NFC opponent that could run us over.
I never thought the Cowboys were better than us (we would beat them And the other NFC teams in the regular season). But an easier path to the SB benefitted them. Again, maybe I am the only one to adhere to this theory!