Go keeps it core feature set very minimal by design. The end result is a language that is almost as fast as C++ and almost as productive to write as Python. If you care about performance, but want to work with a small engineering team it doesn't get better.

Sure you could use Rust to be a tiny bit faster in some use cases. But it's also less productive to work with for your team. You could use Python, it's a bit more productive but performance is 40x slower.

The value of Go is the balance it strikes.

That being said, yes a good enum type in the language, ideally like Kotlin's approach would be ideal.