Skill and specialization

Addressing the matter of "output equality" , Jon Henke writes:

It's almost axiomatic that, as US society becomes wealthier, we become more specialized. And as we become more specialized, we require greater skill, knowledge, etc in order to produce that wealth.

A virtuous cycle: specialization increases output, thereby increasing wealth. That stimulates demand, thereby spurring greater specialization. But does this actually raise the level of skill needed of the average individual? That demand for skilled labor increases doesn't entail a decrease for unskilled labor. Moreover, the individual with skills doesn't necessarily have to acquire new ones. New skills will be needed as economic development continues, but as society becomes more specialized, your typical member needs fewer of them to eke out a livelihood.