The big benefit is that you get more than one elevator per shaft. For skyscrapers the amount of floor space wasted by elevators grows exponentially by the number of floors.
Say you have a 5 story building that needs a one shaft elevator. 5 floors tiles 100 sqft per floor is 500 sqft of wasted shaft space. Then say you have a 10 story building that needs two shafts. Now you are wasting 10 floors times two shafts or 2,000 sqft. And so on.
An old and terrifing solution to this was to use two shafts and run a continuous loop of open door elevators.
Say you have a 5 story building that needs a one shaft elevator. 5 floors tiles 100 sqft per floor is 500 sqft of wasted shaft space. Then say you have a 10 story building that needs two shafts. Now you are wasting 10 floors times two shafts or 2,000 sqft. And so on.
An old and terrifing solution to this was to use two shafts and run a continuous loop of open door elevators.
https://m.youtube.com/watch?v=Ro3Fc_yG3p0