Tipping

There are several things I still do not understand.

For example: I am told tipping is mandatory in America because employees earn less than minimum wage so we are topping up their pay.

1. Is this true in all industries?
2. Are all these employers breaking the law?
3. And if so why are we so complacent about it?

I'm not against tipping, or a commission-based pay structure. The opposite extreme is a place like Switzerland, where there is almost no tipping and service is so bad you often wonder if you are in a candid camera skit.

But why is a tip based in the size of my order? That seems arbitrary as well. For example if I am in a restaurant and I order lobster, is my service better than if I ordered chicken tenders? Is there another way to calculate tip that would align it with actual quality of service? And what about repeat service? If I am happy with my hairdresser I can assure you I will return over and over again. What is that worth in comparison to a one-off tip?