Look at what happened to Kubernetes. They rewrote original Java code in Go and it's a mess because of Go's limited abstraction capabilities. Sure there's an element of rewriting in a new language and attempts to force idioms, but there's also the fact that Go literally hacks in special cases for generics, unavailable to users. They recognize the need for generics, but haven't implemented them, which is a problem for a complex project where abstraction might be useful.

Richer type system, richer concurrency, richer tooling, greatly advanced and advancing runtime, interoperability with multiple languages on the JVM, a naming system that doesn't cause frustrating workarounds a la the Kubernetes ObjectMeta / TypeMeta / "v1alpha1", "v1beta2", "v1" nonsense ...

Go is the language that taught me to really appreciate writing things in Java.