are so superior to the athletes back in my day it's ridiculous.

Your statistic regarding the average athletic ability going down is one I believe. I suspect there are many less kids in the bottom 2/3's of athletic ability who stick with sports anymore. They move to other pursuits.

But the top 1/3 are not only amazing athletes, the development programs are superior, and they tend to focus on one sport.

I don't see the decline coming anytime soon.