I'm curious if you think the same thing was lost with the transition from reading man pages and first-party documentation to going to stackoverflow or google first (at least, I assume the former was more common a couple decades ago)

What was lost in that transition was the required quality of that first-party documentation decreased; generally that first party documentation simply didn't contain enough information, so you needed to determine things empirically or read source code to get more information. I do think the culture of "copy-and-paste from stackoverflow" harmed the general competency of programmers, but having more third-party information available was only a positive thing.

Before 2022 age of modern AI, man pages, SO and Google all were the results of humans, not AI fabrication and hallucination.

A lot was lost then too.