I think it was a mindset issue and fire power. United frustrated Chelsea out of the match. Every man and his dog knows Mourinho plays the averages and drills that into his players. When they are still playing a drab shit match after 75mins their whole entire world is focused on waiting for a mistake, mentally they are still on it. Chelsea at least wanted to try but just got beat out like many others. Their problem is Chelsea are simply lacking up front, Morata is the Pogba of strikers needing everything just so, even Giroud gets more mud on his kit than him.
Hazard whilst a very good player can not shape a game like Silva either as good a player as he is. He tried a bit but between himself and lack of good movement off the ball up front they quickly got trapped. I did notice a few times he could have been getting stuck in to when he was just walking. Call it harsh but i bet my last penny Pep would say the same. It is strange in a way. I saw a few moments Pep would be going fucking apeshit at Chelsea's closing down. Mainly because they were already close to play but not pressing, if taking part in play at all still; and the match was there to win.
Make no mistake Mourinho's anti footy still wins him a lot of games just not as many as it used to. Chelsea just didn't have the fire for it imo.