That is what Bundesliga fans have been thinking for a decade now, that Dortmund is strong enough to compete with Bayern Munich, but the truth is that Bayern Munich won 11 titles in a row. That doesn't quite speak in favor of Dortmund's competitiveness in the Bundesliga. Bayern can count on winning the title even when they show signs of weakness and that is bad because those are the moments that Dortmund should exploit, but they don't.
Bayern Munich tries every season to build a stronger squad than the previous season. And they spend a lot of money to add talented players to their squad. And this is why the party is so strong. On the other hand, Dortmund management's main goal is to make money by making certain players somewhat experienced and selling them at high prices. Dortmund's main target is to do business. Their goal is not to win the title. Every season they sell the best player in their squad. Since this team's goal is not to win the title, naturally we see Munich's dominance in the Bundesliga every season. The Bundesliga is now completely one-sided. Before the start of every season, we know that at the end of the season, we will see the Bayern Munich team as champions.
It is not Dortmund's management main goal to make money from great talents. The real problem is that they can't keep their super talents because they are not able to pay the same salaries as the big clubs. And a player like Haaland would have never signed a contract with them if they didn't include a fixed fee that he can leave the club for if someone is willing to pay it. It is like Ajax Amsterdam which has a similar problem. Once they find one of those super talents like Bellingham, they have no chance to convince these players of staying for a long time when clubs like Real Madrid are already rolling out the red carpet for a transfer.