I don't think Harry Maguire would have been called up to the England national team if he was overrated. That's why it might be a bit harsh to say it's exaggerated. He definitely has talent and it wouldn't be right to claim otherwise. However, he is very error-prone and this causes big problems in the teams he plays for.
It's really a big joke if someone think Maguire is playing because of his big name, he should become a brand ambassador if he's a bad player. People always forget 1000 good deeds for one fault, so that's why vast majority think Maguire is a bad player.
Maguire is a good player, he good in build up since he has a good long ball pass accuracy and clearance.
Harry Maguire performance could be said to be not very reliable in defense, he made several defensive errors, but at different times he was able to do crucial things for Manchester United. He is very good in terms of ball control, although his performance is not very impressive, but in terms of holding the ball Maguire is very good. Even though his performance is mediocre, his presence still really helps Manchester United in terms of defense and attack.
Maybe it was for this reason that England coach Gareth Southgate entrusted Harry Maguire with a position when England beat Italy with a final score of 3-1 for England to win.