I agree with you that Champions League will be more competitive next season. The Leverkusen team is very strong despite not having many star players. On the other hand, Manchester City will try to strengthen their squad next season. Reigning champions Real Madrid have already managed to strengthen their squad by adding Mbappe to the squad.
Bayer Leverkusen will make sure they're having their top prime in UCL next season because the concluded season, they fought with fierce strength and Xabi Alonso was there to make sure they're having a long run. You're absolutely saying the truth, from next season we will experience the most challenging UCL tournament and none of these teams will relent with actions and performance. Every other elite club will make moved to strengthen their club and we totally understand how the matches will go.