A solution might be optionals, which might require sum types, which might require generics (which Go just learned), which most definitely requires a more complex type system, which almost certainly involves longer compiler times.
Is that all worth it? I don't know. The Go team certainly didn't think so.
Languages that I'm aware of that do solve this are Scala, Rust, Kotlin to some extent, Haskell... languages which do not have a reputation of being stable, easy to learn, easy to read and understand, compile quickly, etc.