Is the excellent tooling not also a property of a minimal language? Lisp has the "least" syntax/semantics and the best tooling, because it's so easy to write tools. Go has more complex syntax/semantics, but still much easier to wrangle e.g. control flow out of an AST, compared to other Algol derivatives.

I fully agree with the enums thing—that’s by far my biggest gripe with the language. But even still, I can be a lot more productive in Go than I can in any other mainstream language, including languages that have sum types (Rust, OCaml, etc) which isn’t to say sum types make me less productive but rather that those languages have other productivity issues that outweigh the benefits afforded by sum types. Basically, Go gets a whole lot of little things right that most languages miss, but everyone fixates on “generics” and “sum types” which are, overall, quite small things IMHO.