You can think of Go as the modern representative the Plan 9 and Oberon schools of thought -- their answer to (and replacement for) C and C++.
The fact that it was developed at Google is incidental. That's where Robert Griesemer (Oberon) and Rob Pike (Plan 9) and Ken Thompson (Unix, Plan 9) and Russ Cox (Plan 9) and Ian Lance Taylor, etc., happened to be employed.
Well I don't know who are those people. Reasonable people would think Google would not let employees simply re-writing major chunk of existing code for production services in Go. So tons of huge projects in C++/Java/Dart will remain in same languages unless the product itself is sunset. Even then also Go will not be used to write OS kernel, device drivers and such.
So where ever else Go is used it is decent enough.
Wasn't YouTube rewritten mostly in Go several years ago? Java and C++ won't be displaced as the primary languages at Google, but I think Go is in the top 4 languages they use (along with TypeScript).
