If you are getting a minimum wage of say $15/hour as a waiter, the same minimum wage as everyone else, the 15% to 20% tip for average to very good service era is past.
Your tip might be $1 to $3 for average to very good service per person served. The total amount of tip income in uniform minimum wage areas will be far less.
These smaller tips will be much better appreciated and worked for if untaxed (by the federal government at least).
The government figures on 8%. That’s what you have to pay tax on. Anything over that is supposed to be declared as well of course.