From the start, Manchester United's pass rate was above 70%, but unfortunately unexpected things, such as a mistake that was feared to have occurred in the match against Sevilla, would not be surprising if Manchester United ended up being eliminated due to bad luck. Maybe if the Red Devils appear with their usual defense led by Martinez and Varane then there will be no doubt about winning the two legs.
But indeed time cannot be turned back and Manchester United must try again starting next season, but if they manage to finish in 4th position until the end of the season in the domestic league, then they will not be in the European league again. This time I totally agree with you that Sevilla this season is very lucky to qualify for the semifinals and I think if they still hope for the same luck against Juventus later, I think they will be eliminated.
Erik Ten Hag should have already know the record of Manchester United not winning Sevilla before especially the fixtures they've met previously in the Champions League and Europa League.
Manchester United literally got knocked out as a result of Erik Ten Hag's fault, winning the game and you brought in player to attack more when he should have brought in players to help defend the game. Martial was a vitall player for United that night.
Sevilla deserves the winning because they deserves it, David De Gea and Harry Maguire was part of the second fixture that witness both of those player's playing badly.
Even if Erik Ten Hag might have been aware of Manchester United's history versus Sevilla managers always have to make judgement calls based on the current circumstances. It is impossible to say whether Martial presence would have affected the outcome of the match and it would be unfair to put the defeat entirely on De Gea and Maguire. Football is a team sport thus mistakes by one player might occur at any time. It is crucial to give Sevilla credit for their triumph because they ultimately prevailed because they performed better on the day. Focusing on how United can improve for next matches by learning from their mistakes is more beneficial than placing blame.