Should the NVD be deeply involved in all of them just to provide the most accurate security score? That’s an impossible ask.

This is a false dilemma. If the task is truly impossible, that’s not a valid excuse to try anyway and fail repeatedly, especially if doing so causes negative externalities. Numbered scores with decimal precision are not necessary to the core functionality of a CVE database and there are plenty of alternative solutions which would minimize harm and scale more economically.