I think technically a URL/URI is only supposed to contain ASCII characters, and certain things that expect URL input will want ASCII only. However, all modern browsers can convert from Unicode to punycode (in the domain name) and percent-encoding (in the path). So I don't really understand why browsers only let you copy the percent-encoded form easily.
When visiting the page (at least on Firefox), the location bar displays the intended characters, but when copying it you get the percent-encoded form. If the reason for percent-encoding was just to make scams more obvious, shouldn't the form shown in the browser interface also be URL-encoded?
By the way, it seems like that is a much stronger argument when applied to domian names than when applied to the part of the URL after the slash.
They seem to have that warning on every single page of catalog.archives.gov. That solution seems much easier than figuring out whether each individual item requires a warning or not.
- Non-tech-savvy users might not instantly recognize example.xyz as a domain name. When you discuss your site in person, you might have to explain the TLD, whereas with .com, .net, .org, this isn't an issue.
- If the same domain name but with a more popular TLD exists, people might accidentally go there instead.
- Some outdated validation code (such as a regex to match valid email addresses) might not recognize the TLD, especially if it's one of the long ones. I'm not sure if this problem actually exists, but it could.
If Star Trek taught me anything, it's that most aliens look like humans, except for some bumps on their forehead. Hodgkin's Law of Parallel Planetary Development.