Why do you think it’s accumulating over generations? It hasn’t been recently in Iceland, at least:
Stefánsson’s team scanned demographic records in Iceland for the average paternal age starting in 1650. From 1900 to 1980, as the Icelandic population transitioned from agricultural to industrial living, the average paternal age dropped from 34.9 to 27.9 years. In the subsequent 30 years, however, thanks to better education and higher contraception use, the average age has gone back up, to 33 years in 2011.
Why do you think it’s accumulating over generations? It hasn’t been recently in Iceland, at least: