During the 1970s, multiple fitness companies tried to capitalize on the "air shorts" craze. And given that we're all not prancing around in britches that resemble inflatable diapers, it's safe to say that trend crashed hard.
But what if air shorts did catch on in a massive way? Sure, the health benefits sound suspect (not unlike those conferred by jogging around in a garbage bag jumpsuit) but humanity writ large would look like gargantuan morons. We'd all be too busy laughing at each other's idiotic trousers that war and crime would dwindle to doodly. In fact, the only crime on this hypothetical Earth would be loving air shorts too much.
So yes, inflatable bloomers could have saved the human race, but we had too much good taste to let them. We don't deserve the pneumatic paradise they promised. Here's a 1971 ad for air shorts in case you need some zippy copy to resurrect this civilization-saving miracle garment:
This may well be the easiest, most comfortable trim-down method you've ever tried. All you do is slip into these astounding new slenderizing shorts and inflate them with the little hand pump we provide. Then merely do a few simple exercises, housework or any usual daily activity. What happens after that is likely to amaze you. The puffy, snug-fitting pockets of air which surround you actually work to provide gentle pneumatic support plus effective massage while they generate additional body heat.