I believe PSG is an overall better team than Dortmund and should easily win over them. PSG are the top team in Ligue 1, they has defeated Barcelona in the quaterfinals, which is a second team on La Liga. While Dortmund is the 5th team on Bundesliga who defeated Atletico Madrid which is the 4th team in La liga. Every stats shows Dortmund have an easier path to semifinals.
The Munich vs Real Madrid would be the ultimate battle. The winner of this high stake match would be the favorite for the championship title.
PSG is indeed the top club in League 1 and there is no doubt that their performance in the domestic league has always been superior for years, but in the Champions League? I'm not sure that PSG is superior to Dortmund, while Dortmund is also an elite club in the Bundesliga and if you compare their competitiveness, Dortmund is in a more competitive club, while Liga 1 is not that competitive, so PSG is able to easily beat their opponents who are actually weaker than them because does not have a superior squad like PSG. Against Dortmund is not an easy thing for PSG but PSG can still try to win if they really prepare a truly effective strategy. Victory over Barcelona cannot be a benchmark for beating Dortmund easily because Barcelona themselves received a red card at that time.
Bayern Munich and Real Madrid will be a big match and are eagerly awaited by most people, it will be like seeing them in the final match. It would be more interesting if Bayern Munich and Real Madrid competed in the final, it would certainly be very exciting and tense, but unfortunately they have to meet in the semifinals and only one of them can advance to the final. I think Real Madrid will probably beat Bayern Munich.