You are shopping in a mall and want to go upstairs. Note that the escalators have stopped. You can choose to use the normal stairs or the elevator, or move to the forbidden escalator.
If you chose the last option, then we have some bad news for you. You have put yourself at risk as electric stairs are not designed to be used as regular stairs.
In case the escalator has stopped due to a mechanical problem, let's say the brakes have suddenly stopped working. So the stairs can be destroyed at any time.
Besides, you have no way of knowing when they will start moving again, so you might fall.
Plus, electric stairs are designed to carry only a certain load at a time. When people walk up the stairs, the weight changes. When the conveyor belt stops, the weight may go beyond the limit and the escalator may collapse.
Another reason why it is not advisable to walk on these stairs when they are prohibited is the "broken stairs phenomenon".
Every time you ride or walk on a properly functioning escalator, your brain marks it as a moving object. It adjusts the motor control of your legs and the balance mechanisms of your inner ear to match this movement. Even when you see that the escalator is apparently stationary, the brain unconsciously recognizes it as an escalator. So it feels strange to the body.