They always win their league Ligue 1 which is something they have done for many years. You made good point that PSG stats in Champions League knockout games are better than Inter Milan. Inter Milan has won Champions League three times before but PSG has been strong recently even getting to final in 2020. While past records might show PSG ahead in friendly games these do not always reflect how they play in important matches. At end numbers can tell us something but how team plays on day of big game like Champions League is what truly matters.
PSG have had strong domination in Ligue 1 which in fact was harmful for their performances in Champions League. Quality and competitiveness in Ligue 1 are worse than in Champions League, so PSG were familiar with such intensity and competitiveness and they played important knock out matches in Champions League against strong opponents. With this careless approach, PSG were punished many times by giant clubs in Champions League.
PSG seem to do better in this season and they are going to win their first title in Champions League from a good strategic change three latest seasons. If they win this final, it means more than a title but also proves that they have been switching to a winning strategy for their club developments.
I don't know exactly about what stats you guys are talking about but Inter managed to win in Munich and draw in Barcelona, not too many teams would be able to do something like that. PSG have beaten Liverpool at the penalty kicks, than Aston Villa, which are a good team but no more than that, and yes, they did well against Arsenal. I am more impressed with a team that beats Bayern Munich and Barcelona rather than Liverpool and Arsenal.
I disagree with you in times of competitiveness when it comes to France Ligue 1, in fact the ligue 1 for me is a league I will refer to us a farmer's League, if the league is that competitive will not be having a repeated winner almost every season. The intensity in the champions league is different, in the Champions League you are to meet champions of various leaves, for the fact that PSG came to this point wasn't exactly as a result of the fact that they were too exceptional in their style of play, in fact i believe if they had met a club like Barcelona during the knockout stage or probably the semi-finals, they would have gone out by now, Arsenal were not just attacking minded and offensive as I would have wanted during their last encounter if not they won PSG during the group stage.