They are there for emergency responders. When the lift is switched to "fire service" with the fireman key the door close button actually will work as a close the doors right this instant button. Furthermore the doors will no longer open on their own. You'd have to hold down the door open button to get the doors to open. Pressing it briefly activates "peeking" mode where releasing the button will close the door back up.
See https://www.youtube.com/watch?v=mMBnJal9lhA [warning loud music] for how a fireman would use the fire service in an elevator during a fire.