I think "trust-less" is more what I'm getting at though. In the 90s and early 00s the whole, "don't reveal anything personal, assume anyone you don't have a history with as if they might have malicious intent" was still very prevalent. That only changed when the early versions of social media really started to catch on. My mental mile marker for that happening has always been when Facebook no longer required an edu email to sign up (2005), but I'm sure you could argue it happened earlier.
There are plenty of reasons we should go back to that mindset and AI bots making it incredibly hard to verify that you are talking to an actual human maybe the thing that pushes us back toward that mindset.
I've had many conversations with many people my age (mid 30s) about how we went from "don't post anything about yourself" to "post your entire life online" around when Facebook got big, so I don't think it's something that only I experienced. There's another commenter on this post saying something similar and I remember being taught about "internet safety" in middle school, so maybe it's a generational thing.
Earlier (pre-eternal september) usenet was definitely different though and I think much more like you say - sadly that was before I was old enough to get on-line, so I never saw it.
I don't recognize this description of the Internet from any time after 1985 onward.