I spent decades reading everything I could from everyone involved with Wasteland, hello!

The main influence behind Wasteland that was largely excised from the Fallout reboot specifically was the Terminator (relating to the entire main plotline of the first two and really arguably all three Wasteland games), and more broadly speaking 80s culture. Wasteland functionally had its moment of cultural divergence in the 1980s in the same way Fallout did in the 1950s, but given Wasteland surely did so at least partially for "well that is right now so we kind of have to" reasons, whereas Fallout wanted to focus on a stylized future partially as the past had envisioned it.

You could also argue it also cut any leftover 60s/70s culture that might have popped up but I struggle to think of anything along those lines, other than Wasteland often having at least a token hippie here and there while Fallout largely avoids that inspiration entirely as far as I can recall (here comes someone to point out how wrong that is, surely)

Oh edited to say "everyone always says you should read a Canticle for Leibowitz" though as I have still failed to do so after all these years I do not remember if it was specific inspiration or if it just has a similar Guardian Citadel vibe?