Dortmund made a big mistake by letting such a player go. If they add some players like Arling Haaland to the team then the team will make a big impact in the Bundesliga next season. Because there are no special players in the Bayern Munich team.
Maybe you are the only one who thinks there are no special players in the Bayern Munich team, because maybe you don't really know the players in the Bayern Munich team. It's true that many of the players who used to come from Dortmund were good when they were in other teams so the price was also quite expensive because Dortmund did sell players with potential and didn't often sell players whose potential was still lacking. I also don't really understand the pace that Dortmund has taken in terms of selling and retaining their players.