If Dortmund really wants to get the Bundesliga title, it actually very easy, like what happened last season, its one step closer to the Bundesliga title, but its like Dortmund gave up not getting the title even though it very clear that if they win enough matches, Dortmund can get the title.
however, we have to accept this fact that Dortmund will not be too concerned with the title but more with producing new talents and if for several seasons Dortmund does not sell its reliable players, perhaps Bayern munich and Dortmund will always compete strongly for the Bundesliga title every season.
It's not a new thing, they choose to make money from their youngsters instead of utilizing them to get trophies and they've been the strongest team in the Bundesliga and probably had got the title from Bayern Munich if they kept most of their players in the club over the years, all they do is scout young talented players get them for cheaper fee and develop them into future world class players then sell this players for a very huge fee top other top European clubs when they've Proven themselves.
For instance imagine if they still had Sancho, Haaland, Jude Bellingham and several other top players they sold, i think the team would had been very tough for Bayern Munich to handle and such team would perform well in a Champions League competition but no Dortmund choose the Financial benefits from player sales over trophies.
But why though? Wouldn't it make more sense if they won the cup and then sell their players? I mean if they win and then sell, that would cause the players to be at least a bit more expensive, if they kept Sancho and Haaland and Jude and then won the title this year, they would have made 300+ million from them (and remove release clause from Haalands contract).
This is going to be tough for them to keep finding young talent, it is not that easy to get them and they may end up with a few seasons where they are not making that much money which will hurt them even more financially. They should aim at winning the title as quickly as possible so that they could sell their players for a lot more money and do a lot better.