Tactical Surfing down a Staircase

When you think of tactical movements with guns, you would think of deliberate movements, covering all angle and cool postures.
Tactical movements down a staircase should be just that, however, these guys from Russian Systema Serbia may know something that we in the U.S. don’t.
These Russians are surfing down a stair case.
The first thing that comes up is how practical is this? And, why and when would you ever do this?
Other than to look cool.
https://youtu.be/ha7OJh-pYug

Anyways its still fun to watch Not sure why tactical school is teaching this technique, but it’s definitely strange to say the least.
What do you all think?