Dybala is either world class or near world class and would improve any team. The only problem with Dybala is he is likely to be too expensive. Manchester United have a poor squad with way too many holes in it, for example, we don't have proper wingers or fullbacks and we need another quality CM and AM. Recent history suggests that Manchester United's transfer budget is around 150m per season. Dybala would likely cost 120m to 150m so that is pretty much our entire transfer budget spent on one player. Dybala would be a fantastic signing and improve our team, however, we desperately need proper fullbacks and a winger before we can even consider a support striker or #10. Buying Dybala would be like buying an expensive marble flooring and granite bench when you haven't fixed the hole in the roof and rotten foundations. For the price of Dybala, you could probably get Thomas Meunier, Fekir and Leon Bailey with money left over for a decent left-back or paying Jonathan Tah's release clause.
If the Glazers are willing to significantly increase the transfer budget then Dybala and other superstars could be considered but until then United should fix the foundations and the roof and stop drooling over the granite benchtops and Italian marble flooring as it's outside our budget.