The line also eats an insane amount of people on an attraction.
Theoretically if small world has a 30 boats that each hold 20 people, 600 people are soaked up by the attraction. This is regardless if they stick with 2 loading docks or add a 3rd one.
If Small world can push 3000 people an hour and has an hour long line with 70% capacity going to LL. 900 people are soaked up in line.
If we up capacity 5% hourly capacity is 3,150. Now there are 945 people "soaked up" in line. Up the hourly capacity on multiple attractions and you can get a few thousand people in lines without increasing wait time.
It has to be... G+ is the affordable option. It would have to be priced high enough that most people don't have it. IMHO the $150-$250 express pass price at USO would be far too cheap at WDW and would sell out every day and the lines would be swamped.