If you wait no more than 15 minutes for anything, you can get on a lot more than before - and the stuff you actually want to do. And there’s a finite number of things you need to do before you feel like you had a good day - hence the record satisfaction at Universal.
It’s kind of counterintuitive - you’d think that being able to get to more in a day means you would actually want to do different things - but reality is that people opt for a second ride on FoP or Everest or Hagrids before a first ride on something like Primeval Whirl or Stormforce. Those rides exist (well, not PW anymore) to give people short-wait things to do on days when the popular things have long waits.