Careful now. This system is no zero sum, and putting it in capital letters doesn't make it so. Coin flipping is, parimutual betting is, but lines at Disney are not. Balking, dynamic costs (the cost to a customer of a ride increases with line wait time), mixed queue strategies
these all contribute to the analysis far beyond a static zero sum game.
First, common sense. After FP+ many attractions now usually have long waits they rarely did before. If you assume attendance hasn't increased, etc etc, the only difference is FP+. OK?
Second, crowd behavior at Disney can be well modeled with fluid dynamics, and FP+ is clearly one of the forces that affects that. It has changed, and that's why.
FP+, according to public Disney statements, was designed as part of
MDE to make customers stay at Disney World and not go to other Orlando attractions. FP+, according to their patent application, is part of a crowd management system. Its logical end game is reservations only rides.
You may believe the mean wait time is the same, but the median is a better measure of a customer's cost to ride, and I believe that has significantly increased, with similar SB at headliners and higher SB at rides previously with little SB.
FP+ is difficult to understand, significantly reduces spontaneity, and creates lines where none were before. But, it clearly enables Disney to move toward eliminating the SB line, thus addressing the number one complaint (standing in lines too much). The cost, though, is guest confusion, something that must be addressed.
Disney has shown their reluctance to invest in new and more awesome rides (of the Harry Potter class), so they need to move toward somehow entertaining customers who only get a handful of rides, and have a lot of free time on their hands. Maybe more stores where they can spend more money?
Lines are certainly longer for me.