Dortmund runs this business well. they set up factories to create talented young players who would make a lot of money for the club.
for years, Dortmund has been doing this.
I think dortmund goal to sell Haaland is nothing more than business management and it doesn't make a big difference to other clubs in the Bundesliga except for Bayern Munich.
As for the purchase of players who are quite experienced, such as Sebastian Haller, it is only aimed at strengthening his position and existence in the Bundesliga. Basically football is a very profitable business for those involved in it. dortmund does not have big ambitions to win the league title, dortmund is more interested in printing young talented players and will sell them later after the player has a high selling value.
This difference is clearly visible, and that's why Bayern Munich has always dominated the Bundesliga for 10 consecutive times and the possibility of this season still belongs to Bayern Munich.