By the standards of the day, when Java was released it's standard library was pretty comprehensive: in addition to covering most of the c-ish stdlib, it had networking and web-aware apis.

It did set a new standard in a way that was very beneficial for the languages that came after it: you're not an ACTUAL language if you don't have a "good" standard library, and I can argue that "good" was defined by Java more than C++ or anything else at the time.

I also don't see any new languages, while more modernized, that have substantially pushed the envelope further to be the new gold standard of a minimum batteries included stdlib. All I could probably say is various threading/concurrency apis, but Java has added a lot of that too over the years.