I know you’re being sarcastic, but if chrome could, with perfect accuracy, indicate if this was “the site you want”, why not do away with the url?

Mind you, I’m not suggesting to do away with linking, as some rando suggested this implies. (While chrome doesn’t show the protocol prefix, it still copies the prefix when you copy the url, so imagine a similar ui.) But for most users, wouldn’t a ui that shows “server identity” in some more user-coherent way be what they want?

In particular, do subdomains help or hurt phishing detection?

You're making a hypothetical based on "with perfect accuracy"... but the much simpler change here (www vs. no www) is not done "with perfect accuracy", as clearly outlined by a bunch of comments in this thread.

So you're saying we should show all users www., just because that one site in a billion that shows a different non-www. page, for that one user in a million that would even notice that difference? Chrome is a browser for the mainstream people. The feature you're asking for is for power users and extreme edge cases.

If we could, I'd be all for it. Have an option that says "show URL bar or not" and by default hide the URL bar, optionally show the whole thing. Especially on space-constrained devices like cell phones where every pixel counts. Just show the page's title.

I think we're a long way away from that ideal, though, and some web pages may not be designed with this ideal in mind.