This is what went wrong.
Is a midfielder judged by a skill of their footwork? Clearly the clips that I showed you are actually showing that Carrick can handle high pressure. Players went to give him pressure and the clips showed that he was still able to make the pass without losing it. You don't need a high level of footwork to be a midfielder who can handle a high pressure. There are many ways to handle pressure from the opposition players without losing the ball and it's not just playing with your feet with high level of footwork.
Well I watched all United games not just nearly. Look mate, you were the first one who mentioned a few games of when Carrick couldn't handle high pressure game with no proof. I showed you clips for proof.
Your clips haven't proved anything? The first clip is Carrick playing a pass while surrounded by players, well yes. Carrick is reknowned for his passing.. who doubted that... the second clip is him running into space while facing forwards, and the third clip.. he is in acres of space, so where is this magnificent footwork under pressure that you speak of.
Look having played CDM - trust me when I say, footwork is very important in that role especially in the modern game where focused pressure to stop teams from playing out via their DM is very important. You don't need the footwork of a winger - although the very best like Verratti have exceptional ball skills, but you do need to have some tricks in your locker to avoid being closed down.
Being very comfortable on the ball, allows you to have the confidence to shield the ball, get around the guy who is pressing you and being able to create your own space to make the forward pass. Guys like Busquets, Verratti are geniuses in that regard.. you can't press them because their footwork is too good. I've seen Busquets pull off 360 spins, when he is being put under pressure and still keep the game moving forward.
Video of Pirlo's dribbling skills, another level to Carrick.
If you think footwork is not important in midfield, you either don't pay enough attention to the game or you haven't played in midfield. If you are a coward on the ball in midfield, and you always pass back or sideways under pressure, your team will struggle to get a foothold of the game and they can impose their game on you.
Obviously Carrick isn't a complete donkey in this regard, he is a champions league class DM but he is definitely lacking in the footwork respect compared to the world class DM's of the past 10 years and the clips you showed don't prove that he can consistently throughout a game, handle a press.. turn his man and keep the game moving forward. Even Fletcher was better than him in this regard, he was more comfortable in tight spaces and wouldn't pass back under pressure.
People confuse Carrick's brilliant passing ability for being comfortable on the ball. Being able to spot and execute a pass is one thing, but being able to carry the ball under pressure while your back is to goal and you've just recieved a pass from your CB's is a different skillset. It is the skillset which separated Scholes from guys like Gerrard/Lampard.. who when put in centre mid where space can be congested, didn't know how to create time on the ball.. he had more silkiness on the ball and better awareness in tight spaces.
Since LVG came, he has actually gained in confidence under pressure but there is no doubt at his physical prime, he was not great under a press.