from time to time someone has to point out that tipping is not required in switzerland. that's true: it's not required, there's no legal responsibility to tip, but - _not_ tipping is considered down-right rude and very bad manners. you don't have to tip 20%, but normally you give around 10%, especially if you have received extra attention.
(minimum) wages are higher in switzerland, but the cost of living is as well. you can't get by on only your salary as a waiter, the tipps are part of it.