Luis Enrique managed to shape the mentality of his players when facing Inter Milan so that what happened was that they were so dominant and I think it was not just about luck but the preparation efforts they did very well.
Of course there are many factors, but I think Enrique's role is quite dominant. Football is always about luck plus hard work. So all have a role in making PSG champions. So PSG I think were lucky and they worked hard to win. Their hard work in the league makes them comfortable to participate in the UCL because they are very superior just look at their point difference. Then Enrique also has good players, they don't have many injuries. Then in the first knockout phase they had a good mentality worked hard and got lucky in the penalty. In the quarterfinals they met Aston Villa I think it was luck, they had an easy opponent. In the Semifinals and Final they worked hard and they got a happy result. IMO