We don't know what Edin Terzic's plan and Borussia Dortmund's management actually are by selling some of their best players, it could just be that the sale is because they want to replace them by buying even better players so they can bring Dortmund to win.
If we compare Dortmund with Bayern Munich this season, it seems that Dortmund have not been able to compete Bayern Munich.
But everything can turn around in an instant because in a football match we can't really predict exactly.
Dortmund is purely a business club and it's not surprising when they can develop young talents, so if there is an offer from a European team who wants to make up for it at a fantastic fee, Dortmund will let the player go. But indeed the competition between Dortmund and Bayern Munich is endless even though Dortmund always loses its talented players every season and I think it will continue to happen if Dortmund still uses its mindset to always sell the players needed by the team to win the Bundesliga title or other competitions.
I agree with you. Dortmund's main goal is to do business. They scout young talented players. And they develop players with experience. And sells players for a lot of money. And this is their main goal. The team is not aiming to win the Champions League or Bundesliga title. The club made a lot of money selling Haaland last season. They will likely trade Haller next season. This season Dortmund will probably add more talented young players to their squad.