Just a guess.
If the traffic flow of the elevators can be made more efficient, they may have fewer shafts?
Elevators and mechanical services use floor space ($$$). The higher the building the higher the percentage.
One shaft ~10’ x 10’ times 100 floors times $$$ square foot/month adds up to real money. Plus the car and maintenance are not free.
Yes. This is easily the biggest reason for “smart” elevators, to be able to have fewer of them.