Dude, when was the last time you saw a wait that was more than the time it took for the next theater to open in COP?
That's kind of the point: if COP is only loading half their capacity, there isn't really a capacity problem is there? There is enough capacity in the park for people to get their overall ride counts up, but if they don't WANT to ride something, that capacity gets wasted.
That's why adding attractions is almost a zero-sum game. You add new attractions, people want to ride those, and whatever attraction is at the bottom of the demand list gets bumped out and closed. Now your overall park capacity is equal, or even sometimes less than it was when you started.
Worse yet, adding attractions tends to increase overall park attendance so now you have more people in the park, who all want to ride the same ten rides, and not enough capacity for them.
Go count the number of attractions per-park at Disneyland and then come back and try to continue this argument with a straight face.
Disneyland is still miserably overcrowded, even with more attraction capacity. They had to go thru and tear out trees and benches and planters because they were so worried about how crowded it was.
But you could still walk into the Lincoln Theater on a hot summer afternoon and take a nap.
The current trajectory won't change until enough of the faithful adopt this mindset.
If enough people stopped going they wouldn't need Fastpass at all. But if they stopped needing Fastpass though, all those people would want to come back. Then they would need Fastpass again.