I don't think that it's because Manchester United was a big team that was why he was not able to deliver the truth is that any player coming to Manchester United will not play at his best because the environment in united is not a good one that players can do well
It is a topic on Serie A, not Premier League, and I don't think discussions on Manchester United is matched with this topic.
And Vlahovic indeed became one of the bad historical records, becoming one of the players with an extraordinary transfer fee but his contribution was very lacking. This is only expensive in price but nothing special in his performance sof ar during the season. Because, even Juventus wants to terminate the contract and wants to sell him as soon as possible.
Vlahovic did not meet requirement of Juventus but it is similar to Manchester United. A star player can not perform at his maximum capability if around him are not too good players. Juventus in recent seasons have had big problems in their squad and other players must be responsible for their individual bad performances and a team performances in general too.
Vlahovic has underperformed since his transfer from Fiorentina to Juventus but he only co-shares responsibility with other players. He is not the only reason for Juventus' bad performances in three latest seasons.