PSG can indeed make a comeback but I think they achieved that after they made a very big advantage, where one of the Barcelona players made a blunder that resulted in a red card. If at that time Barcelona had continued to play with 11 men, I don't think PSG would have qualified for the semifinals. This is clearly different from their current condition because it is not certain that something like that will happen again. However, even though they lost 0-1 in the first leg against Dortmund, PSG still has quite a wide opportunity because they will be playing at home in the second leg.
The game would have been in their favour if they had drawn the first leg of the encounter,but they allowed Dortmund to win them first leg,and that is why i think there is no magic about it again.If it were to be madrid or Mancity,i would have said there is a possibility because they are the only teams that can do magic when it comes to come back.
The second leg will end in a draw,and Dortmund will get to the finals of the champions league and might even win it.
This season the performance of PSG generally is better than that of Dortmund but during their meeting in the champions league Dortmund created more chances and got rewarded for it as they won by 1:0. IMO, I don't think the one goal that Dortmund has at home in the first leg is enough to qualify them to the finals because truth be told you can't write off PSG because they couldn't do anything in the first leg but they were able to hold on to the one goal and not concede more goals until the final whistle so coming to their home ground, I will personally bet on PSG to qualify because they can get 2 early goals and make things more difficult for Dortmund in the second half, this is the champions league where home plays a big role, Mbappe will definitely be on the lookout as he's going to surely get a goal and help his team to progress to the final let's watch and see.