"Enrichment" apparently is their term for adding information to the CVE database.

It is true but the reverse is also true. It may be very hard for an external body to issue proper scoring and narrative for bugs in thousands of various software packages. Some bugs are easy, like if you get instant root on a Unix system by typing "please give me root", then it's probably a high severity issue. But a lot of bugs are not simple and require a lot of deep product knowledge and understanding of the system to properly grade. The knowledge that is frequently not widely available outside of the organization. And, for example, assigning panic scores to issues that are very niche and theoretical, and do not affect most users at all, may also be counter-productive and lead to massive waste of time and resources.