For a start, I think that decision would not have been overturned until the ref had viewed several camera angles... and viewed the key one two or three times. No way would it have been a "quick check". But anyway, even if it was, the enormous damage that VAR does to the game was very clearly on show on Sunday when Tryone Mings scored an equaliser to make it 2-2.
A massive goal for him, at Old Trafford. He should have been taking a glance over to the linesman and going apeshit in celebration, thronged by his players. Instead, he wasn't sure whether or not he was offside, so it was like handshakes and taps on the shoulder.... which transmitted to the crowd who had muted celebrations. To a greater or lesser extent, this happens almost every time a goal is scored... so the way it kills the joy of the game is usually a bit more subtle.
VAR has its pros and cons. If there were never any grey-areas... and decisions where instantaneously available - like the case of goal-line technology, then it could be great. But that's never going to happen. As painful as last night was, it's far better to accept the decision. Ideally ban the guy retrospectively and move on.