It's unfortunately somewhat common these days and personally I actively avoid any place which does this. At least it's only somewhat common rather than the standard so it's still possible. Couple of examples:
https://sushiconfidential.com/wp-content/uploads/2024/07/sc_... "3.5% Living Wage Surcharge added to each bill which allows us to provide the service you have always enjoyed!"
https://www.pacificcatch.com/menu/ "NorCal - A 3% surcharge (5% in San Francisco) will be added to all Guest checks to help offset the rising cost of wages and benefits. This is not gratuity."
They need to price it in to the menu.
I run Union electrical jobs and I don’t list out every fringe benefit they receive on an itemized invoice. It’s $163/hr with everything baked in.
If restaurants want to pay a living wage, charge more money for food.
Because increasing prices by that percentage is too hard?