Then the restaurant owner is the slave owner
The owner provides the venue. The diners had full discretion whether the server would be paid $2, $20 or $30 an hour.
I’m not defending the owner. I think most restaurant owners are scum. My girlfriend is a server and the folks she works for are money-grubbing bastards.
But, she does have nights where it is possible to earn $200 or more from her diners so she sticks around. But even then she pays 5% of her TOTAL SALES back to the house, regardless of what she earns in tips.
Her choice to stick around. I guess better the devil you know :)