I wonder if replacing the type system in Go with the one in Rust and adding native Actor model support would be doable. Or if GC and compile time would regress too much. Modern languages without good sum types just seems like such a lost opportunity to me.

What would be the point? Why stick with Go if you want so deep-reaching changes?

That what I often wonder, if one is going to start using a new language why go? Rust at least it gave one memory safety and not having to use GC make it more stable usage of resource as the discord article have already pointed out. Seem like go is just google's .NET, every big corp need to have their own language.

Go is a complete and simple language, and this is a fairly objective claim.

Unless by "incomplete" you mean it could have more features. But C++ and Rust (and Java) have been piling on features for years, with no signs that they will ever slow down or stop, proving that they're also "incomplete" by this definition. IMO this is really just a result of there being too many cooks in the kitchen, and a lack of leadership committed to saying "no" to feature requests.

This is also why using Rust or C++ requires every organization to agree on a subset of the language they will utilize. Rust isn't as far along this path, but it's heading in the same direction as C++.

But with Go, every organization can use the complete language. That's how simple it is.

Go has been used by many organizations to build stable, large, and scalable systems that have been operating successfully in production for many years now. That's how complete it is.