For Maguire a change of the location, or the league to be more specific, would be the best way to move on for him. I think that his career is more or less over in the Premier League because it is the same people in the end who are watching him and who are giving him the bird if they see him making any mistakes. Minor mistakes will already be an issue because he has no room for error left, which is bad for a defender as the press will attack him as soon as he makes a small mistake.
Of course Maguire has to see the opportunities that exist because it is very difficult for him to develop his qualities in the Premier League so he needs an easier League for his career. Apart from that the interest from the top teams in Serie A in him opened up opportunities for Manchester United to release him in this summer's transfer window. For the value of the release maybe Manchester United can adjust well so that the Serie A teams can reach it because we know the Serie A team finances have not been very good in the last few seasons.
The time for the transfer market is still long. I think some teams are still actively trying to sell players or buy players in this summer transfer window. Manchester United are still trying hard to convince Atalanta to agree to their offer to sign Hojlund in this transfer window.
It is not so much about finding an easier league, but about finding a new place to play where he isn't immediately picked by everyone as the one to blame for mistakes and losses. This is his reputation at the moment and as soon as he makes mistake, it was his fault when the team loses the game. Manchester United is not the team where he is most likely to recover and play his best.
But "
Manchester United turn down £20m Harry Maguire offer from West Ham" It won't be easy for him to find a new club as it didn't go unnoticed that he had a bad time and no club would want to pay too much for him now, but instead try to make use of the situation that Manchester United wants him out of the team. This could still take a couple of weeks until Maguire knows where his career will continue.