It seems obvious to me that when people idolise the 90s and before, they're mostly talking about the fact that there were still significant areas of life that had avoided complete atomisation. I don't think many people are really arguing the law was better, or that peoples' material conditions were super amazing, just mainly that it was actually slightly achievable to go out and TALK to people.
It at least feels, to significant numbers of people, that atomisation has significantly increased in the couple decades since 2005. And for all the horrible things you can rightly point out about the 90s, being able to actually have a fucking friendly conversation or a friend or two, basically on demand, certainly made it a lot better for people.
I remember as a kid we would regularly go to the town square, have a friendly chat with the baker, have a friendly chat with the greengrocer, friendly chat at the corner shop, get some advice from the ironmonger, talk to some weirdo while we waited for a bus, regularly asked people for directions, etc. All in a single morning. Because going out of town to shop was much rarer, we were known locally as a poor family, so half the shops gave us an unofficial discount and a smile. And all that didn't happen because I was a kid, it happened then because the bakery is now a chain where you can only order on a computer screen, because the greengrocer and ironmonger shut down, because the corner shop is now a supermarket and the staff change every week and they give 0 shits because they only pay minimum age, because there is no bus where we're going now (and talking on the bus is seen as weird now), because nobody is supposed to need to ask for directions anymore. These are all things that have changed just since the early 2000s, and whether they realise it or not, this is what made the 'vibe' that people miss.
The 90s could've been hell on Earth, but if you got to experience it with some fucking company, then people will be nostalgic for it, and I don't think that's necessarily wrong.