That is the big difference between a club like Bayern Munich and Bayer Leverkusen. I do think that Bayer Leverkusen can and will play an important role in the next Bundesliga season, but will they be able to go beyond the 80 points mark again and maybe even target the 90 points like they are doing this season? As you said, if they can manage to keep their squad for the most part, they will still not be able to repeat that season. But there is already a ton of rumors circulating that Wirtz is a transfer target for Bayern Munich and several other players are being observes by big clubs. I guess they have to expect to lose 2 to 3 players.
Bayern Leverkusen players will be targeted by big clubs in the top five leagues in Europe, and Bayern Leverkusen cannot turn down those offers. Even if Bayern Leverkusen cannot repeat what they did this season in the Bundesliga next season, they will surely finish in the top four of the Bundesliga next season. Bayern Munich will do their best to win the Bundesliga title next season.
This is what is not liked about the Bundesliga, every time there is a good player from another team, Bayern Munich always targets and buys him. That's why it is difficult for Dortmund to win the Bundesliga because all their players were sold to their rivals. This will also happen to Leverkusen next season, especially now that Leverkusen players are starting to be targeted by European teams and there are even rumors circulating that Xabi Alanso is also being targeted by Bayern Munich to replace Tuchel at the end of the season. So it can be predicted that Leverkusen next season will not be as strong as now. I'm not sure that next season Leverkusen will be able to compete again for the Bundesliga trophy.
Bayern Munich is doing that, so they will not have a serious challenge for the Bundesliga title. That is why Bayern Munich keeps dominating the Bundesliga all season. Bayern Munich will keep buying good players from other Bundesliga clubs because they want to sell their best players to raise money for their clubs.