What's the point of group interviews?

I had an interview at a museum for catering servers. I wasnt told it was going to be a group interview and they said they needed 2 years of experience, yet a bunch of the candidates were HS students. Wasted 1 hour and half by being asked to do silly exercises with the rest of the group such as broken phone or write exam answers on situational questions such as what would you do if you saw broken glass.

All for min wage + 'tips'.

What are the expectations here? I've also noticed the more confident you are (i have years of catering/banquet experience) the less they want to hire you.​

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