I think the FIFA Club World Cup says a lot about the EPL being the most competitive league there is because of all the top clubs PSG encountered throughout the season only EPL clubs were able to give them much problems.
PSG has beaten Arsenal and Liverpool and won the Ligue 1; by this logic, the Ligue 1 is the most competitive league.
You can't use one match to determine which league is more competitive. Manchester City, which was the other team from the EPL, were knocked out by a team from Saudi Arabia, does that mean the Saudi league is as good as the EPL, since Manchester City has won the league four consecutive times previously? Football is not like that. The fact that one team beats another team in a knockout match doesn't mean the league is better.
The Premier League is competitive, but it's still just a few top teams like the Serie A and La Liga. I mean, we can deny it all we want, but we know that the winner of next season's EPL title will be between Liverpool, Manchester City, Chelsea and Arsenal. In the same way, other leagues have just 2 or 3 people who are real contenders for the league.