That should be the case and they should be able to learn from Manchester City to build a team not in an instant way by recruiting lots of star players, PSG failed last season when they implemented this.
And I also see that they have not developed or have not been able to achieve achievements on the European stage because PSG does not have fierce domestic competition so this team cannot compare in strength to be able to rise even better.
As we have seen in the last few seasons in League 1, no competitor has put pressure on PSG in the title race.
This is what still makes it difficult for PSG to measure their own abilities when they are on the European stage because the opponents they face in League 1 are quite weak opponents and cannot put that heavy pressure on PSG. If only PSG could get enough opponents in League 1 every season, perhaps PSG's own strength would not be what it is now and could even improve more than it is now. So when PSG faces other teams on the European stage, they will become more accustomed to withstanding pressure from their opponents.
The competitiveness of a league has a big influence on improving a team's performance and this is what PSG is currently experiencing, for example this season PSG's performance is not very consistent in League 1 but that doesn't make them threatened at the top of the standings so it's not a big deal if they didn't win, there was no greater motivation for the PSG team and because of that it also made it difficult for their quality to improve to be able to compete in the UCL competition.