Not only Belllingham but Dortmund has given birth to quite a number of talented players and they always sell it when there are teams who dare to offer high prices. Although able to replace with other players, but I think the concept that De Borrusen built was quite brilliant because in addition to pursuing achievements but they also always won business, they were also always able to be the main competitors in the Bundesliga.
I completely agree when you say they are brilliant in terms of business, but I disagree if it goes to the realm of achievement that you say. yes indeed they have always been the main competitor for Bayern Munich, but being a competitor is not enough because there must be gold ink they must record, whereas in more than a decade in the Bundesliga itself they were unable to stop the dominance held by Bayern Munich. With their ability like that (creating many talented young players) they should be able to utilize it more in terms of achievement and that they have not done until now.