Key life hack against thieves - with this button the car is extra secured. With the key trick, however, the system can be reactivated at any time - usually with a simple click on a button.
In Mercedes, for example, it is enough to press the close button on the key twice in a row, i.e. with a “double click,” to deactivate the keyless system. There is no overarching standard for all vehicle manufacturers and models with which keyless go can be switched off.