With the signing of De Ligt and even though Bayern Munich lost Lewandowski. It feels like they are a stronger team now than they were 2 months ago. They needed better defensive players and they've now got De Ligt with a 5 year contract. In terms of attack, they've got Mane to run down the wings and create more chances.
It seems to me that Bayern is getting an excellent result in this transfer market, the team has improved very well. Lewandowski is not a loss for Bayern, he himself wanted to leave the team, and keeping a player who wants to leave is pointless, he will not do much good if he is unhappy. And Juventus is losing another strong player, and this further weakens its squad before the new season.