In addition to the players and the coach, even the factor of luck plays a role, why City could not defend their Champions League title, because post-match penalties are more of a lottery where luck plays a big role. Can we say that PSG was unlucky in the match with Dortmund? I think so, they hit the crossbar so many times, although they were definitely stronger than Dortmund. So the result comes when there is a certain chemistry in the team, when everything works out in the best way and even luck is on your side.
Luck in football is just a small thing and it is not a reference even though sometimes we see it is real. Man City failed to qualify for the next round because several players failed to execute penalties so they had to accept defeat. Dortmund played quite neatly and solidly when facing PSG so it is natural that they managed to beat PSG both away and at home.
Although statistically the game was more dominated by PSG, Dortmund managed to take advantage of small opportunities to score goals. PSG must build a more solid and strong squad next season so that they can find opportunities to win the title. Luis Enrique must be able to make the players more solid and able to work well with each other.