I'm not sure I understand the metaphor? Let me know if I'm off base.

If the suggestion is that putting things in the standard library makes them better, I disagree. My experience with Python for instance is that a "batteries included" strategy results in some phenomenal packages and some borderline abandoned packages that are actively dangerous to use.

To riff on your metaphor, the federal government designs the arterial highways, but the state, country, and city/town officials design the minutia of the traffic system. If the federal government had to approve spending on replacing some street signs or plowing snow, we would have a terribly impoverished transportation system.