Have you tried OCaml? With the latest versions, it also has an insanely powerful concurrency model. As far as I understand (I haven't looked at the benchmarks myself), it's also performance-competitive with Go.
Also, at least at the time, the community was really hostile, but that was true of C++, Ada, and Java communities as well well. But I think those guys have chilled out, so maybe OCaml has too?
So far, I like what I've seen.
Its a really nice language
$ dune init project my-project
$ dune build
That's it, now you have a compiling project and can start hacking.Though as a side note I see no open gitlab positions mentioning ocaml. Lot of golang and ruby. Whereas jane street kinda always has open ocaml positions advertised. They even hire PL people for ocaml
I haven't looked at benchmarks, though, so take this with a pinch of salt.