To be clear: they're tipped workers doing some non tipped work things. They make over the regular minimum wage over the course of their shift. They just don't get a different pay rate when they spend 15 minutes running descaler through the coffee machines or sweep the floor.
Tipped work is bullshit and the government saying they won't tax tips is only going to make the problem even worse. Make tipping not legal. Servers absolutely don't want that because they make bank for the job they do.
Law overwhelmingly overrides contracts, and these types of "haha, you chose to give up your legal rights" contracts are completely unenforcable, but you have to have the means to challenge it in court in the first place. 🤡