What do you care how the salary is calculated and who it comers from.
Well, I do care. If it is a service charge, "I" pay the wages of restaurant staff, and the owner keeps the profit from the meal price.
If (as done in Europe and other parts of Latin America) there is no "service charge" to pay staff wages, the owners have to pay their staff's wages from "THEIR" profit.
Now, don't tell me that if there was no service charge that the prices would be actually higher to compensate for the wages.... not true. It is a difference whether you charge a 500 pesos pizza or 750 pesos pizza...the same pizza...
If the pizza place does add taxes, it might seem that in case service charge is eliminated and wages paid by the woner in full, and the tax is mandated to be included in price, that in that case a 500 pesos pizza + taxes would go up to 750 pesos under "no additional taxes/service charge scenario". But no!!. They will NOT increase the final price. Why? Because there will be new competition that opens up to sell 500 pesos pizza final rate. Why? Because there is hefty profit. Where there is a "higher than regular" profit to be made competition comes in and runs the prices down until the equilibrum is (re)established. (Economics 101).