Yeah this is so much worse than 5yo kids working in coal mines a hundred years ago.
Sure its not exactly ideal, but if this is a kid whose parents own the franchise and he is legally working and being paid at the family business its better than him being left at home on the xbox.
My grandpa brought my brothers and I to work at the family business when we were pretty young. Mostly it was stuff like sweeping and cleaning tasks, nothing really cruel or stressful or that we could screw up.
A bit different than customer service but convenience stores often have the kids helping out too.