While everything you say is true, there are other forces at play as well -- many people have much more time at younger ages. 15 years in, many of us have kids/

While everything you say is true, there are other forces at play as well -- many people have much more time at younger ages. 15 years in, many of us have kids/responsibilities which are another non-tech reason for "greying out" (ironically perfect name!). It's easy to conflate these two forces, which are different but both contribute to this effect.