I'm not sure what the claim is here. Kids need diapers for a few years, which we can basically assume is constant. Meanwhile, lifespans keep increasing (espec

I'm not sure what the claim is here. Kids need diapers for a few years, which we can basically assume is constant. Meanwhile, lifespans keep increasing (especially in the past average-lifespan, say 80 years), and I assume adult diapers are used for significantly longer per person. At even a 1:1 birth/death rate, given a long enough average lifespan, I would expect more adult diaper sales unless we find better / permanent fixes for whatever causes the need for adult diapers in the first place.