Last time people were ecstatic about go compilation speed, the speeds cited didn't even hold up well against gcc.. The go compiler is not very fast, but as you point out the features of the Go language makes it amenable to fast compilation.
What kills compilation performance for larger C/C++ projects is include hell and managing build dependencies, which as you point out is mitigated in language with modules.
It is a good sell when the audience only knows about C++ compilation issues.