Really? My wife is ~70, and not all that technical, but she knows (for example) that "maps.google.com" is a Google URL. And she even knows that "mail.google.com.assholes.io" is not a Google URL.

It's just anecdotal, I know. But I find it hard to imagine that most people don't understand URL hierarchies. I mean, people who use computers commonly organize files in folders.

But maybe that's becoming a lost art, as most new users just have mobile devices.