The reason is just simple that it will be maybe end like it was with Bellingham and Haaland , because other Clubs has more Money that they can use for players.
Dortmund hasnt any rich guy behind there back and have to make there one Money from players and stuff.
But yeah i guess Edson Alvarez can bring something special to Dortmund and the whole team.
That's the reason why this club is not very attractive and it's very difficult to develop to fight for titles. In addition, they also don't have the drive of the rich behind them, so the way to go is to cultivate players bought at a low price and sell them at a high price. Edson Alvarez is the next project Dortmund will be capitalizing on and they have proven that time and time again in every transfer window that has opened.
Dortmund played their way with the tactics of making stars from young players then sell them with a good profit so they can bring more players and so on.
Right now, it seems that Edson Alvarez is the one that seems close to join Dortmund, he is young and might improve with the team. There isn't much rumours about other players to join.
Dortmund's talent monitoring team is very keen to see the potential of players who will develop and they often buy players at below standard prices, but when they develop after being trained they will provide fantastic bargaining values. There are lots of examples of what they've done and for me it's not interesting because the club will never develop in this way or maybe they never intended to win a title in a certain league?