I’m a licensed skydiver and the planes we jump out of go about 80 mph. Passenger airplanes go MUCH faster and higher than that and the wind speed alone would rip yer skin off.
also skydiving isn’t exactly something that typical commercial airline passengers would ever be interested in doing. If you’re not properly trained, you’re gonna have a bad time.
In addition to what others said about weight, training, the logistics of moving that many people at once, and other common sense problems; the most times (~80%) something goes wrong with airplanes is during takeoff or landing where you couldn’t feasably safely jump out of the plane anyway reducing their effectiveness even further.
Instead of a regular backpack can I just bring a parachute as my carryon?
Weight. Chutes are heavy and means more fuel use and less range with less people. Which means more flights, which means more planes, crew, maintenance, parts, landing fees etc.
It would be easier to strap a large parachute to the plane which has been done on small aircraft
I’ve seen a concept of an airplane that can eject sections of it’s hull, each equipped with a large parachute. This can solve the problem of “how to put parachutes on each passenger including kids, disabled and panicked and teach them how to use it”. Also it doesn’t require the plane to maintain certain height, speed or angle for parachuting.
But of course it will add extra weight to carry, because not only they’ll need to install big parachutes, but also ejection system and something to seal off ejectable sections.