PSG has always been an aggressive team. When they have scored 3+ goals already, they now go on full defense to not let the opponent have a chance.
If we look into the recent season in French and English league, the difference is starling. Unlike English Premier League, the Ligue 1 just have 34 games. In those 34 games, PSG conceded 92 goals. While the winning team of Liverpool in 38 match conceded 86 goals. While for Chelsea it was 64 goals.
There could be reasoning that Ligue 1 has less competition than Premier League, but what I want to justify is Ligue 1 is more aggressive than Premier League.
The fact that PSG consistently dominates Ligue 1 means they don't have enough strong teams to challenge them. If Ligue 1 teams were as strong as PSG, they might not be as aggressive.
They will face Chelsea in the final. It would be an extraordinary achievement if PSG could win the Club World Cup. This achievement would complete their season's achievements.
Paris Saint-Germain will surely win the final against Chelsea. I know it's a given, but it's normal for it to happen. They currently have the best team around and can boast a bench that could be another top club starting lineup, so unless they make mistakes, victory is in their pocket.