Dortmund of course they do have extraordinary strength and I agree with you that Dortmund can get to the final of course not because of luck. but in my personal opinion Dortmund's strength and performance are indeed good and of course we saw Dortmund successfully beat PSG in the UCL semifinals in the 1st leg and 2nd leg of course this really proves that Dortmund is a good team that has a strong defense and of course I do too saw how difficult it was for PSG to break through Dortmund's defense during the semifinal match. So now it's clear that in my personal opinion the same is true, namely Dortmund not because of luck in advancing to the final but because of the quality and results of their hard work.
but of course in the coming season, Dortmund will definitely try as hard as possible to win a trophy in the UCL even though the competition is very tight and of course Dortmund will definitely have the potential to become a strong team again in the UCL, yes, even though Real Madrid's squad is getting stronger, of course Dortmund will definitely fight to be even better than the season that just ended.
Borussia Dortmund is surely one of the good clubs in Bundesliga but in last season their performance was not good enough just because of this they are ended at the fifth spot and having spot into Champions League final was purely due to their luck because they were having not good enough squad, but their defense were good which help them for having better results their attack was not good enough so now in this season they have done some work and having improvement.
Due to their business model of having youngsters and selling them after development things have never been ideal for them to having consistency into their club which is important for the clubs which wants to stay at the top and having good results as well as we have some good changes we will have good improvement in few clubs which will surely create good challenging matches at the top which is trademark of Champions League in last few years.