Serious and trustworthy according to whom, exactly?
The term peer review was virtually non-existent prior to the 1960s. And despite that, nearly everything in modern society can ultimately be attributed to breakthroughs that happened prior to the advent of peer-review.
I think you misunderstand how accessible the Internet was, and the history of open-access journals dating back to the late 40s. arXiv started in 1991. None of it explains why the peer review started surfacing in published books.
It does correlate perfectly with when modern scholars point to when the institutions were captured.
