Why elevator close buttons do nothing

In most lifts installed since the early nineties, the door-close button is disconnected for everyone except firefighters. It still lights up. That is the point.

What everyone sees

You press it, the doors close a moment later, and the button clearly worked.

What is actually happening

Accessibility legislation in much of the world requires lift doors to stay open long enough for someone with limited mobility to enter. Overriding that with a passenger button would break the requirement, so in most modern installations the close button is inert in normal service and only becomes live in firefighter or maintenance mode. The doors were always going to close on schedule. Engineers call the button a placebo control, and lifts are full of them — as are pedestrian crossings and office thermostats.

Why it stays hidden

Because the feedback loop lies convincingly. The button lights, the doors move, and confirmation bias closes the case. Nobody stands in a lift running a control experiment.