It's because a lot of regex validations (including earlier versions of Angular) have a regex that ends in something like \.[A-Za-z]{2,4}$ (this is the end of t

It's because a lot of regex validations (including earlier versions of Angular) have a regex that ends in something like \.[A-Za-z]{2,4}$ (this is the end of the regex in Angular 1.15, it also doesn't support brackets or quotes in the local part, poor showing from Google) At the time when they were written, gTLDs didn't exist, so the longest a tld could be was 4 characters (.info, .mobi). It's pretty piss poor futureproofing to be honest.