Emergency building escape line - GIF

[Frank S]

Obviously controlled friction descent device. I have questions, would there be one of these safety belts and cables for every occupant of the apartment? or would the line have to be reset? Is there a device for rapid rewinding? How would it be adjusted for the weight of a small child? What about a situation where there are guests?
I noticed he tossed the spool containing the tail end of the line on the balcony this seems to be a sure-fire way to create line entanglement as it free spools. Unrestrained cable or line spools like this are unpredictable at best at worst they flip and flop until creating a tangle as bad as a bait cast reel in a professional overcast as the anglers call it.