Odd that you say that, because the language that's most similar to Go here is Java, with its checked exceptions. The same reasoning that led to Go's error codes (that you should always handle your errors) led to checked exceptions. The fact that people generally think checked exceptions are a bad idea is a point against Go, not in favor of it.

Checked exceptions are superior to Go's error return codes anyway, since they make it easier to bubble your errors up to your caller.