Required step by HR at a lot of companies I have worked at. Theory is not just culture fit but that you might get blind spots for the urgency, for some skills, etc. So a team that cannot evaluate those interviews to see if they are a decent person in general as a last check. Bonus points if it’s others who will work with the employee, but not actually required.
P.S. I’ve had people fail miserably at the Be A Human step. People who did the phone or tech interview well, have since written books and are Important In The Community, but were just horrible in that part of the interview. Important check.