In fact, teams like Manchester City also failed and thus, I think it is not wrong to assume Dortmund will not reach the Champions League final next season. Because after all, to stay strong in the race for the Bundesliga trophy is also the fact that Dortmund still often fails. Therefore, Dortmund simply do not have the quality to consistently reach the Champions League final, because basically Dortmund are still not strong enough to be a title challenger team. Therefore, I say there is nothing wrong with such an assumption, because the reality is that Dortmund are also not always lucky even though indeed, Dortmund always managed to have great players and sold expensively to elite teams. But when it comes to competition for trophies I think it is clear that Dortmund are still not strong enough.
Just because you are a good team, doesn't mean that you are going to UCL finals. The issue is that there are only two teams in the world who can go to UCL finals, and that means we are going to end up with only two good teams there and all the others not there.
There are more than two teams that can be considered good, and this is why I think it's obvious that we can't see Dortmund, because I can name 10 teams which are better. This season them being on the finals was a big shock, nobody expected them to be there and nobody thinks that they are going to be able to do that twice in a row neither, they just don't have the talent for it.
Only thing I want to see before everyone changes, is a City vs Real finals, because if we do not see it in a few more years, City will have to revamp the squad mostly, and we won't have majority of who they have now. KDB may move, Silva may, Grealish may, and many other players may move to other clubs in a few years, or maybe even retire.