They let go of players who don't meet these standards. Especially with low-paying and short-term contracts, they are essentially telling the player to leave the team. Robert Lewandowski continued his magnificent career with Barcelona after leaving Bayern Munich. He didn't live up to expectations last year, but he was very good until last year. Bayern Munich let him go even knowing this. So, there are some unchanging realities for Bayern Munich.
Bayern Munich seems a bit like a team of robots, and I'm not talking about the fact that they play extremely well, but about the fact that you should never get too attached to the players almost. Only in rare cases, as happened to Thomas Müller.
In other circumstances, such as Lewandowski, they didn't have the problem of selling him to Barcelona once he got older. Same future that i imagine will happen to Harry Kane.