Typically in the enterprise HR software space, the customer does not want to buy all their components from a single vendor. If they want a culture fit quiz, they do not go to their ATS (applicant tracking system) vendor for it. They go to an organization that has specific skills in this particular area, and has onboard psychologist(s) who can demonstrate the validity of said quiz.

The code behind such a quiz is usually trivial - the intellectual property not so much.