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.
Just by looking out the clubs we have already gotten an insight of how next season champions League will look like and the clubs that has a very higher chance of winning and also in the case of Liverpool I would say that they should just focus on the premier League for now because with what they did on this finished season I don't think they will survive on the champions League and also they are still going to go through a little declining in performance as there coach Klopp will no longer be with them next season, so getting use to the new coach will certainly take some time and also Arsenal on the other hand should also focus on the premier League more because that's were they have the higher chance on, however in terms of real Madrid they have already equipped themselves and they are ready for the champions League.
if you critically analyse what's going on in both EPL and champions league, it's almost as though everything is working for the favour of real Madrid and Manchester City cause at the moment, they are the most prepared team to win champions league and the EPL. Liverpool to my opinion isn't close to dream of winning the champions league and with a new coach that's going to take care of the team from the coming season, we aren't sure what he will be bringing to the table and we are not certain wether or not he will have what it takes to bring out the best in the players.
Most likely, Liverpool will struggle more this season compared to last season and if they don't tighten there seat belt, it's possible that they wouldn't get to top four on the premier league table. For the EPL, Arsenal and Manchester City are the teams that will bring the heat to the champions league and it would have been easier for An EPL team to dream of winning the champions league hard it been that real Madrid doesn't have anceloti and incredible players all choked up in his team and not ready to drift away anytime soon. At the end of ty day, it's likely going to be a question of real Madrid vs any team that is able to fight his way to the finals iether from the EPL or any other league.