Leverkusen cashed in a big total of about $157 m (around £116 m) by selling Florian Wirtz to Liverpool. Also Jeremie Frimpong was dropped for roughly $38 m, mounting up to over $195 m. So its really a smart move for a club without billionaire owners

and covering the costs of the club.
Flipside Leverkusen have definitely become weaker. Now former Ajax manager ETH is hunting for youth talent like PSV's Malik Tillman, Mark Flekken, and Ibrahim Maza. I'm not expecting any title push from them next season, it is all about stability and development for their future profit. The best I could say, it is not anything collapsing, it is something like rebuilding.
It is realistic that the player who contributed significantly to Leverkusen in the last two seasons is replaced with young players, financially the Leverkusen team has indeed experienced a very large profit but the steps they took are very risky for the decline of the Leverkusen team next season.
Ten Hag will find a difficult job again now, to return to being champions will not be easy for Leverkusen but I think they just stay in the top 4 is enough and that will be very difficult.