Why is electrical power required at all when the elevatore is descending ? Why should there be a limit on the number of passengers in this case ?

Explanation

When the elevator is descending, then electic powder is required to prevent it from falling freely under gravity.
Also, as the weight inside the elevator increases, its speed of desecding increases, therefore, there should be a limit on the number of passenger in the elevator to preven the elevator from desending with large velocity?