Why don't all browsers simply visually emphasize the TLD and second level domain (or third level in a case like example.co.uk) in any given URL?
Yes, sometimes it is not easy to recognize the real address in a scam URL like "dropbox.com.scam.ru" but browsers could make absolutely clear what the TLD and SLD are.
The version of Firefox I'm on right now does. Most of the current URL is a light gray, while the "ycombinator.com" portion is white which gives much more contrast against the dark gray background of the URL bar. (I'm using the dark theme, but I'm pretty sure the normal theme does this, too.)
Yes, sometimes it is not easy to recognize the real address in a scam URL like "dropbox.com.scam.ru" but browsers could make absolutely clear what the TLD and SLD are.