Well, the guardrails, by which I assume you mean legal and social accountability, were the norm for most of human history, which is why I don't consider the behaviour of anonymous and unaccountable humans on the internet to be "normal". Of course, humans are capable of great evil, but we are also pretty good at building social structures to prevent the worst of it. But those structures don't work so well on the anonymous internet.

> You see this in real life on the streets too.

To nowhere near the same extent, in my experience. Most people in real life are still fairly polite, even to strangers. It's insane to me how rude people can be on social media. Some of the aggressive responses I've received on Reddit (to fairly innocuous comments) I would never in a million years get in real life. (And this is also true of the 90s internet.)