There is a price to be paid for the ease of the elevator.
Like everything else, there is always a compromise- inherent risks and rewards.
To take the elevator is easier than the stairs; it is more convenient, and requires no physical exertion. There is, however, a level of faith and dependence that you don’t find in the extra effort required to take the stairs.
In the case of elevators, you are reliant upon the works of many different people, you never truly know what floor you are on, and you are never fully aware of the condition of the machine. Sure, the button says you are going to the 5th floor, but who programmed the light?
How sober was the engineer who designed it?
Who maintains the cables?
When were the pulleys last changed?
You can’t inspect the functions and conditions of an elevator every time you ride on one; you must rely on others and have faith that they did their job. (I don’t know about you, but I am in contact with lots of folks who do the bare minimum at everything they do.)
With stairs, you get exactly what you see, and you know exactly where you are.
In many situations, more effort will get you where you want to be with a greater certainty. It might be a little slower, and a lot less convenient, but sometimes the most efficient way to get to the top requires a little heavy breathing and some burning quads.