Career earnings growth in the U.S. more than doubled between 1960 and 2017, and the age of peak earnings increased from the late 30s to the mid-50s. I show that a substantial share of this shift is explained by increased employment in decision-intensive occupations, which have longer and more gradual periods of earnings growth...Experience takes longer to accumulate in high variance, non-routine jobs.

That is from a new working paper by David J. Deming.  One implication is that AI leads to lots of angry, frustrated, left-wing young people, and a cementing in of the gerontocracy.