Every season of the Champions League is always tense and full of amazing things because of the matches of many strong and great teams, and for example like Dortmun who unexpectedly can be in the final party with great confidence against Real Madrid.
Dortmund's performance in the last Champions League was just surprising, they played well and were able to get to the final, but they couldn’t beat Real Madrid in the final. Even in the last Champions League final, Dortmund had the opportunity to win the match, but they missed all the opportunities they had in the first half of the match. But in the second half of the match, things changed, and Real Madrid took control of the match and were able to win. If Dortmund utilized the opportunity they had in the first half of the match, then all they would do in the second half was just hold down Real Madrid.
For Liverpool, don't be underestimated because the new coach is not as high as the popularity that Kloop has, some people think too much to underestimate Arne Slot without knowing what he might do with Liverpool in the current season
Let’s wait and see his performance when the season starts. A coach might be a good coach, but his performance might drop after joining a club, so we shouldn’t conclude yet. I am not really underestimating Liverpool, but I will like to see the coach’s performance in the club.
Klopp is already a legendary coach for Liverpool and I think his performances will be hard to achieve once again in the near future of the club and that's why I do not expect Liverpool to perform as high as they did in the last years. Sure , they will fight for top 5 without any doubts but fighting for EPL title will be very hard for them as long as they don't make important transfers and when it comes to UCL , I think winning it it's already impossible for them. However , like you said , the start of the season should give us an idea of what this new Liverpool is capable of.