Modern football does require funds to build a team although sometimes money is not everything, but in football like today money is very important because teams can recruit players that are needed as a step to make the team stronger. This is what happens in Ligue 1 because PSG is the only club that has good enough finances to recruit many players they want, so the competition there is not competitive because PSG has much better quality players compared to other teams.
This might continue to last a long time in Ligue1 as long as there are no other teams that are able to develop like PSG today. In addition to financial factors that can have a big influence on the team, the coach factor can also be a differentiator because a team with a lot of money can certainly get more experienced coaches. And this has happened repeatedly to PSG so that the Ligue1 competition is always easy to guess about who will be the champion at the end of the season because there is no more competitive resistance than the other teams.