I see the approach of Dortmund is like Monaco in Lique 1 and Sevilla in La Liga. In comparisons, Sevilla is a most successful club with this approach. They did not win La Liga but won many Europa League with 6 titles in their history and all came from recent seasons. Dortmund and Monaco have similar approach, buy young players and sell them with expensive price when they became star players but failed to succeed like Sevilla.
Maybe Dortmund wasted too much attention and resources for Bundesliga where they have nearly no opportunity to beat Bayern. Sevilla are different and they mostly focused on Europa League.
Yes, there are a set of clubs who maintain this financial policy which is to scout out potential future stars and nourish them into making them better players. And finally, sell them to the bigger clubs for a huge transfer fee.
We have been seeing these from Dortmund over and over again. They have sold players like Robert Lewandowski, Erling Haaland, Mario Garza, Mats Hummels, and a lot more players in the same manner.
Another team is Monaco who have sold players like Kylian Mbappe, James Rodriguez, etc. I think even though these teams do not rank higher in the leaderboard they make a good enough revenue from the transfer market.