Really good environment for first time workers, allow you to develop many skills that you can carry to future employment. Allows flexible working to pursue other things such as education or childcare.
Cons
Some targets can be difficult to reach and ruins the customer experience as you are more focused on targets for it to look like good service than actually providing good service.
Social heirachy "advancement", absolutely zero health and safety, kitchens are absolutely disgusting. If you knew what they looked like you wouldn't order, trust me.