Servers work their backsides off. Firstly, those trays are backbreaking, then they fill condiments, wrap silver, if they're not finished with that by the time customers leave their tables, and they can't fill condiments while customers are at the table. Sweetener packets must all be turned the same way. Tables must be sanitized, windows cleaned, the floors swept or vacuumed or mopped, often sanitized. Who do you think cleans and sanitizes the bathrooms? Helps get the kitchen staff caught up?