Michigan server who got $10,000 tip says she was fired in ensuing dispute

When did that start? I always thought that 15% was the standard
with their minimum wage per hour has been $2.13 per hour from my working in the 90s and still the same, inflation is out of control, and wven then, 15% is a if you are possibly lucky. i have a problem with overtopping and it doesn't help fix the issue.