I suppose Ten Hag should have learnt from his experience with Manchester United for him to accept to take a job for a team that management has no intentions of equipping the team for him. Perhaps that could have been what Xabi Alonso foresaw that made him accepted Real Madrid offer. How do a club sell out their key players and ain't replacing them to ensure the team make a good performance in the coming season?
To be fair they needed the money when they couldn't win the league. You can't expect Leverkusen to fight against giants like Bayern Munich, when they do not have the same income as them. Bayern can afford to pay anything they want for players, which they do because they have the income, they make much more money than all other teams and when you do that, you end up with best players in the league.
Leverkusen do not have that income, so when the chance comes for them to sell a player for a 100+ million offer, they can't just reject that because when will they ever get that chance again? The difference is, after Xabi won, he was expected to do great last year. ETH is not expected to do that great, I would honestly consider a top 4 finish as a great success for him, but if he ends up being out of top 10 or something, that has nothing to do with the squad he has.