The point is not about validation, it's about conveying semantic information through types. It's perfectly valid to have an email type that is just a wrapper ar

The point is not about validation, it's about conveying semantic information through types. It's perfectly valid to have an email type that is just a wrapper around a string. The advantage is now you and all your functions unambiguously know that the type represents an email (whatever that means) and not a frobinator.