The reason they can use check boxes is as an easy filter, as a credential arms race has made so many certified applicants, and the mean ability in that pool is

The reason they can use check boxes is as an easy filter, as a credential arms race has made so many certified applicants, and the mean ability in that pool is higher as Caplan points out (mostly due to selection, not by learning). Also instead of being hired by a senior worker, you are hired via human resources. It's much easier for HR to require a degree than verifying abilities for a particular role they have only surface level understanding of.