PSG's wealth is not really from another source, the win the Ligue 1 almost every season and they win other sub league titles plus their jersey sales which most other teams do not get as much so their wealth is not far fetched and they also utilise it well with the quality of players they bring in so it may not be all abi their wealth, but it does plays a very vital role that will continue give them that topping edge which most other teams does fail to get so you cannot dissociate their success and strength from their wealth, they all work together.
Despite all this, PSG is a financially rich club. Winning the league title or becoming the champion of other tournaments alone will not get so much money that if they had that much money, they could have taken Mbappe, Neymar, Messi, Ramos and other world-class stars to the team at the same time. However, there are many differences between that time and the present. At present, PSG has let go of all the expensive stars and they have relied more on young players. Luis Enrique has already proven that it is certainly possible to build a strong team with young players. The young talented players that PSG currently has in the team will be seen in a few years who are selling these young talented players to other clubs in Europe at high prices and they are making a lot of money by selling these players.
The reasoning is simple, when you have star players then you rely on your star players, and if those star players do score or do fine, then you end up with great results, but if they end up not doing anything, then you lose.
But when you have a whole team that is nearly equal, then you do not have to worry about anyone shining, because if one can't do it then the other will. I know that Dembele is now seen as the best player here, but remember that Dembele was the player Barcelona didn't wanted, so realize that PSG is the reason why he looks great, normally he is not the reason why they are good, it's all of them. This does include Dembele of course, but it includes everyone, they are all doing great together, that's the point.