The benefactor model nearly always falls apart at the point the owner can no longer subsidise the club or decides to pull the plug for whatever reason. A lot of mega rich owners are in it for political reasons whether it is the Gulf states trying to project a positive image (sorry boys you are still a bunch of tyrants and will always be no matter how much money you spend on your football projects) or in the case of the Russians a bolthole in the West should things turn against them in Russia.
Politics change as Abramovich found out when his visa wasn't renewed. The Quatari's aren't getting the benefit they thought they would from PSG. Resented by many in France and failing to land the top European prize has left them wondering if it is all worth it.
As ever the central dilema for fans and the authorities is how do the rest compete with the super wealthy clubs like Real Madrid Manchester United and Barcalona who require no subsidy but left unchecked grow wealthier and more dominant by the day.