Earlier quoted context omitted.
Plenty of great functional alternatives to Go.
None with the same performance characteristics, ease of use, and ecosystem size. I'm reasonably competent with Rust, but sometimes I don't want to bash my head against the borrow checker or litter my code with copy/clone. Go hits a nice sweet spot, my main quibbles are that there's no native iterators/comprehensions or sum types with compiler checked exhaustive matching. With generics we can get libraries that allow…
Most JVM languages (Kotlin/Scala/Clojure) including Java :) In fact kotlin/java has better peak performance than Go. Main advantage for go is the reduced memory footprint.