Why? Keep in mind in go, you almost certainly don't check the type of the error. Why hold python to a hire standard (or the opposite: why don't you pass errors with types in golang, and handle errors of only a particular type or set of types?)
The answer, in both cases, is of course the same: errors are almost always handled in one of two cases: basically at the callsite (either at the callsite or in the parent function), or they are handled in "main" in some form of catchall.
Exceptions are really great for this. You very much don't worry about the things that might be thrown by a child of a child of a child of foo() that you call, because the abstraction shows that you shouldn't care (unless perhaps foo documents explicitly a particular function it throws). You don't need to waste code or mindshare on something you really don't care about. In go however, you do!