Well, yes. But Java's standard library is also huge and full of deprecated stuff. I have not done a lot of Java programming, but when I did play around with Java, I found myself spending most of the time actually browsing through the standard library's documentation (which is, to be fair, really, really good) looking for stuff.

Also, Java has a head start of nearly 15 years on Go, and the Java community is (or used to be, at least) pretty huge.

Not that this invalidates your point.