I think Dortmund is making a mistake by letting go of young players. Jude Bellingham and Haaland are the two most obvious examples of this. If these two players had stayed this year, Borussia Dortmund would probably be one of the strongest candidates for the title. However, since they run the team like a company, I think the title is something the management does not care about. It seems like the Borussia Dortmund management is trying to buy players and sell them for more money.
What they are doing is not longer a mistake, it is a deliberate attitude and I think it's the way they plan to be carrying out their operations. Assuming it was a mistake, they would have realized the mistake after selling off a few players and see how great they become especially the goal machine Haaland. After Haaland they have built and sold players that are extremely doing well too. Assuming they are interested to build a squad ready to win trophy, they would have been convincing these players to stay with them and achieve positive results together. The fact still remains that they prefer and Prioritize business over building the team for competition.