It is an easy league without competition for PSG. This league doesn't look attracting for investors much as well so it looks like PSG will continue to dominate it for long years. But if we see another team having a rich owner in the future then maybe the champion would start changing more often.
For now it isn't possible unless PSG give it away.
When it comes to Mbappe the reason why he stayed this long is money. Nobody knows the exact conditions of his current contract. It is that big.
But from now on I think he will think of making a change more seriously. Because PSG can't win a Champions League title. For a star like him winning that title is really important, to have a bigger career. Real Madrid is the right place for that in my opinion.
maybe if there are investors who will invest their money, they will definitely not take shares in PSG but will prefer to invest in teams other than PSG which have almost the same performance as PSG to be able to get big results in the future to see the change of League 1 title holders.
like Monaco and Stuttgart, they are strong contenders for PSG if there are large investors who provide large funds to these two teams to get higher quality players who can provide an interesting sensation in League 1.
It is indeed very boring to see the current League 1 which is always boring because there is no strong competition to compete with PSG, whereas at the start of last season I remember Monaco and Brest had very good results but unfortunately they couldn't maintain consistency so they had to lose this opportunity.
and regarding Mbappe, of course a star player with very high quality talent will not possibly risk his youth just for money but will certainly also think about his career and experience in big competitions like the UCL which Mbappe must continue to pursue and one of the biggest opportunities is just join the right team like a team from La Liga like Madrid.