What's to prevent corporations and the rich from taking advantage of this? ie, my job is $10k + rest in "tips"?
Then there would probably be a bunch of sub-bullet points defining whether a tip is taxable depending on whether you have a direct relationship with the customer tipping you, whether the "tip" is mandatory, or at the discretion of the customer, are you in X roles (e.g. barista) within Y industries (e.g. food services).
Also define tips by industry. Service sector. End of story.
I don’t think that saves much in administration costs.