I mean, it wasn't even that security wasn't a thing: the earliest incarnations of the Internet were defense projects, and after that, connections between university networks. Abuse was nonexistent because you knew everyone on your given network. Bob up the hall wouldn't try to steal your credit card or whatever, because you'd call the police.
I think a decent idea is, we need to bring personal accountability back into the equation. That's how an open-trust network works, and we know that, because that's how society works. You don't "trust" that someone walking by your car won't take a shit in your open window: they could. But there are consequences for that. We need rock solid data security policies that apply to anyone who does business, hosts content, handles user data online, and people need to use their actual names, actual addresses, actual phone numbers, etc. etc. in order to interact with it. I get that there are many boons to be had with the anonymity the Internet offers, but it also enables all of the horseshit we all hate. A spammer can spam explicitly because their ISP doesn't care that they do, email servers don't have their actual information, and in the odd event they are caught and are penalized, it's fucking trivial to circumvent it. Buy a new AWS instance, run a script to setup your spam box, upload your database of potential victims, and boom, you're off.
A lot of tech is already drifting this way. What is HTTPS at it's core if not a way to verify you are visiting the real Chase.com? How many social networking sites now demand all kinds of information, up to and including a photo of your driver's license? Why are we basically forbidden now by good practice from opening links in texts and emails? Because too many people online are anonymous, can't be trusted, and are acting maliciously. Imagine how much BETTER the Internet would be if when you fucked around, you could be banned entirely? No more ban evasion, ever.
I get that this is a controversial opinion, but fundamentally, I don't think the Internet can function for much longer while being this free. It's too free, and we have too many opportunistic assholes in it for it to remain so.