Big disappointment must have been felt by all Dortmund fans last season if we imagine that they really became champions but they wasted that opportunity. On the Bayern Munich side they have been the most consistent team as the strongest domination in keeping their throne as the title winning team for the season to come. Nothing will surprise us enough next season because we know Bayern Munich is the strongest team in the Bundesliga and they will be champions again next season.
Moreover, next season Dortmund will again be left by its best player, Bellingham. So they will be back in their strength balancing stage next season. For other teams they are still not too strong to be compared with Bayern Munich, so their hopes of undermining Bayern Munich's reign will be quite difficult to come true.
There's nothing unusual about Dortmund and that's how it is. Dortmund is a competitive team in the Bundesliga, but they are likely to find it difficult to stop Bayern Munich's dominance as the best team in Germany. Dortmund's transfer policy has cost them merit, of course, as they seem to lean more on a business perspective than on team achievements like winning titles.
Dortmud often release many important players in the transfer market as long as they get big offers. Dembele, Haaland, Bellingham and several others are the star players they have sold for big profits.