It is so bad that Dortmund do not even care if selling their players will make the team to be in a bad form, they just keep on selling their players just to generate funds. If Dortmund was never interested in selling their players Dortmund would have been a great team not just in Bundesliga but also in the Champions league. Bellingham is a great player that would have been very helpful for Dortmund but they do not think about keeping players to make the performance of the team good, Dortmund agenda is to sell their players for a huge amount and this has always affected the performance of the team.
This is something that's been going on over the years and they're not bothered about losing their most valuable player because they've got good scouting network across Europe that helps them recruit new youngsters from teams all over the world and to be honest I don't think any team would had been able to challenge a squad that had Lewandowski, Haaland, Sancho, Bellingham and several other top talents across Europe.
I've always considered them a business minded Club because if they really cared about winning a trophy they would had utilitized the players they had instead of developing them and selling them out to others top clubs while it reduces their performance, the sale of Jude Bellingham is really affecting them this season because was their star player but they've cashed in on him and made Realmadrid more stronger.