If a building has stairs and an elevator, most people will prefer to use the latter.
Many modern buildings hide their stairs in some corner behind a dirty door or two. You need to search for them and ask a few people before you start climbing up or down. In most cases, these stairs are poorly maintained because people rarely use them. In contrast, elevators are always easy to find and spotlessly clean.
But, if you need to cover just one or two floors, using the stairs to climb up or down might be faster and more convenient. It also acts as a small, useful exercise for your body.
Another important benefit of this habit is that you will feel that time is in your control, not in the hands of some random machine. Sometimes, the elevator may have a technical problem, it may be in high demand due to increased footfalls in the building or it may be overloaded and hence can’t take extra people in it. In such cases, you may have to spend 2x or 3x amount of time before you can reach your destination floor.
Good old stairs don’t have this issue. If you typically take 1.5 minutes to climb up a floor, it remains 1.5 minutes in most conditions. This feeling of control is good for our mental health.
Of course, some people may have health conditions that prevent them from using the stairs. All others can try to move from “100% elevators” status to at least “50% elevators, 50% stairs” status. It is beneficial in the long run.
Building Administrators should also support this change by making stairs clearly visible, clean and inviting. They can use posters to motivate people to take stairs whenever possible.