I agree, for even if you re-watch the match it is clear that Arsenal were superior to Manchester United at many points, so the fans' outrage is nothing more than frustration at the defeat. After all, even assuming that their goal would have counted, it wouldn't change anything, for the score is 3-1
Being a Manchester United fan is heartbreaking, with no peace of mind and many disappointments.
The fans are tired of these losses. This club is filled with drama!
It's just sad that fans always know what might happen, but the manager doesn't care.
And I hope the next game will see a change. Let's see what Amrabat and Hojlund bring to the team.