In what way does Go do errors better than Scala though? Error handling is _more_ first class in Scala, not less.

I don't think applicative/monadic error handling is an afterthought in any way. There are combinators to recover, for instance. But it's optimized in such a way that you can focus on the happy-path of your code and you get a sensible default for error-handling (short-circuit..just like Go's idiom!)