Xabi was the reason why Leverkusen could compete with Bayern for the title. Losing him to Madrid gave no clarity about club's future. So Wirtz and Frimpong follows him. Leverkusen is officially back as a mid table team by losing those guys. Bundesliga seems to be a farmer league again by Bayern.
Bayer Leverkusen sold their key players; they also left Xabi for Real Madrid, and as you said, it’s a pure fact, Xavi was the one who managed this team to be able to compete for the Bundesliga title. Now they have changed their 2 key players and also their manager. Things will totally be different from next season, and nobody knows if it will be for good or the other way.
I think by next season everything will look new for this club. I just hope Bayer Leverkusen won’t mess up things next season because their 2 key players are gone and the manager is new, which means their new manager, Ten Hag, will introduce a new strategy. They will get 2 players to replace the players. Things will definitely be different.
I maybe fine if Leverkusen only lost their key player, and Xabi still stay, but it's not what happening now. They lose everything that changed their team, especially their manager that helped them to win Bundesliga after a few decades.
This is my reason to be very skeptical about their future. How many times they changed their coach until they found Xabi? i could not even count it.