> In fact, if that was a valid argument, it would be for C++ not having a standard library at all
Putting aside the continuum fallacy, it's easy to understand how the C++ would be better served by having access to a collection of third-party components instead of repeating C's and even Java's mistakes.
The Boost project is a very good example, so as the wealth of JSON and XML parsers.
In fact, this lesson is so blatantly obvious that essentially all mainstream programming languages simply adopt official package managers and leave it to the community to develop and adop the components they prefer.