Apart from all the football clubs so I think Borussia Dortmund's revenue system is a bit different. As we are accustomed to, we see the clubs generate revenue through winning trophies are placing better in the league but I think Borussia Dortmund's revenue system is scouting out younger talented players and selling them for a hefty fee.
We have seen this case for players like Erling Haaland, Mario Gotze, Mats Hummels, and very recently Jude Bellingham. I think the board of Dortmund like the way they make money from selling younger players to bigger clubs for a huge sum.
It is a good method but as mentioned earlier by a million people, winning a title while doing what they do is still a good method. I mean winning a title doesn't mean you can't buy young kids and improve them and sell them. You can do both at the same time. The problem is that they do not have a good football culture that is sustainable, get a good manager, build a formation and a method, and keep playing that for 10 years and see what happens.
I believe that if they do such a thing then they would become one of the best teams in bundesliga again, and rival Bayern again. Before all this Bayern domination Dortmund won a few, they could go back to that if they had some system in place.