Maybe more of a theory than a law, but still:
Any eLearning tool, no matter how openly designed, will eventually become indistinguishable from a Learning Management System once a threshold of supported use-cases has been reached.
They start out small and open. Then, as more people adopt them and the tool is extended to meet the additional requirements of the growing community of users, eventually things like access management and digital rights start getting integrated. Boil the frog. Boom. LMS.