I know mouse and guest were just kidding but if given the choice between nothing and parachutes?

If every third floor had a "launching chamber" with sufficient parachutes (an outdated name--modern ones are considerably more adaptable to base jumping), and a static line to open the chutes for those leaping. You'd only need one openable window every third floor.

Then those who chose to not take this method could take their chances on considerably less congested stairways.