Yeah exactly, there's like zero difference to the compiler. That's why it's such an easy feature. (To be fair you probably also want some syntactic niceties like destructuring bindings.) But clearly in practice, no one wants to define a new named struct type for every function that needs to return an error. I think part of the pain is that, without some sort of "auto" type deduction feature, you force the caller to type out the name of the return type most of the time, in addition to the name of the function. And yeah, if I had type out StringAndError or IntAndError a million times to use a library, I'm sure I'd hate that library :)
