Huh? Go has an enormous and high quality std lib and even larger set of community libs. On top of that its popularity is exploading. I’ve never seen a language rise in popularity as much as Go.
Java exists today in many places where change codebase is a nightmare and keep up software is no less a nightmare so having a more manageable language able to insert itself in the old ecosystem is valuable, but on a moderately new language with nothing so big to be in a state of needing a nightmarish replacement why?
It's like Hy for Python: it's nice, a programming exercise but for what more than the technical piece? How many Python programs need a new language while remain on their own python VM? How many Python programmers want lisp with Python underneath?