[throw310822]

> To be fair, tipping on top of sales tax never made sense

That's a bit funny. Why doesn't it make sense? There is no meaningful relationship between the amount you spend, fixed brackets like 15%, 20%, 30% etc, and the job the waiter did bringing you the food. It's all made up and unnecessary. You can be expected to pay it before taxes, after taxes, 0%, 80%, only for desserts, only on your birthday... It's completely arbitrary.

[pixelatedindex]

Tipping is for service. It’s a charge and like all charges, it’s levied on the subtotal.

If I calculated tip after tax, I’m paying a portion of my tips to the state, and they are already getting their share via sales tax.

[throw310822]

Hm. Tipping is not a charge, is a gratuity- which means that its amount and even whether you give it or not is up to you. You can decide to tip 20% before taxes or 16% after taxes- it's exactly the same. It all depends how much you want to risk being seen as stingy by the waiter in front of you.