That's Dortmund business so far, developing players and selling them at high prices. Yeah although Dortmund sold important players, they can still stay close with Bayern Munich in terms of points, but still they couldn't take advantage of the situation because before they should be have won the title. I hope that in the next new season Dortmund can also be consistent again although they already sold important players again in this summer transfer window. You are right that other clubs every season try to stop Bayern Munich hegemony, but they difficult to be consistent. Now other clubs are improve the depth of their squad, which one of them is Leipzig and it is hoped that with the addition of new talented players, they can can stop Bayern Munich hegemony.
Dortmund have good business for developing their players and selling them on higher price two or three years later, almost every season Dortmund sell their player with higher price and this season Jude Bellingham transfer fees reach above 100 million euro. I don't think with Dortmund priority winning Bundesliga tittle on every season depend they sold important players, new recruitment need time adapted and Dortmund can't consistent to defend important players for long time and always looking for beneficial profit earn from selling them. Business is priority than to be compete for Bayern Munich and how to make rival teams difficult winning domestic league and this style from Dortmund
But how many years Dortmund will priority with their business than getting many trophies? have been 12 years Dortmund not winning Bundesliga tittle and Bayern Munich always become the champion.