What OSI mostly does in that space is giving a definition for "open source" https://opensource.org/osd

Having a definitions for a term is good, as it makes sure thee is a common reference in usage. If everybody uses a different definition it hinders discussion.

If that definition doesn't serve your needs better use a different term (there are more or less related other terms like free software, shared source, libre software etc)

Licenses more or less automatically fall under that definition or not (yeah, yeah, there is a process by OSI for certification, but that is relatively close to the definition)