I’d say it’s reasonably clear that parachutes are not a practical way for meaningful numbers of people to escape a burning building.
All they really need to show is that the number of injuries & fatalities is less than without the Rescue Reel.
You mean a broad steady consistent updraft, or a turbulent erratic one, such as you’d likely find in a burning skyscraper? The latter could easily collpase your chute and put you back into freefall.
No doubt. almost anything is peferable to a 100 storey swan dive 
I may be mistaken, but with the WTC, my memory seems to say that the smoke was pouring out on all four sides of the building.
I suppose with a rapid descent the smoke will hopefully not trouble you too much, but , again wit heh WTC case, the floors that were burning were pretty intense and I’d be interested to see some data on what the cable in those things is made from and how heat resistant they are.
In terms of the number of people evacuated, surely it wouldn’t be too hard to put a small motor in that rescue reel thing to retrieve the cable to let multiple people use it.
As to the congestion issues, would you presume most highrises would give a couple of hours to evacuate. If you have 6-10 people coming down each side and a descent time of what 2 minutes, that’ll get a lot of people out of the building.
If you were really high up, you might get some use out of
a wing suit
This would get you out of the turbulent air around the skyscraper
and line you up on a good landing area before you had to pop
the chute.
Given the choice of jumping, burning to death, or using a parachute that may not help, I’ll take a chance with the parachute.