He is probably the best manager they could have got, and not sure who they could replace him with - I can't think of anyone looking for a job with a winning pedigree like Conte (I am excluding Tuchel due to his Chelsea connections), who they could realistically get through the door. I fully agree they don't play attractive football, but we all knew this when he was appointed, and it was a major reason United didn't go for him when they had the chance to do so.
They'll do OK in the league, as they have enough about them to win a good chunk of games, and they might go deep in a domestic competition, which I think is their best chance of a trophy. It won't be the league title and it won't be in Europe either.