The no tax on tips thing is a mess. Now the feds had to make a list of what jobs allow tips to go without being taxed. Not only is it a big loophole to exploit the government also tells you whether your tips are basically valid or not.
The IRS didn't start requiring business owners to report tip for their employees until around 1980. Even then, unless a worker keeps a running record of all the tips they receive, the businesses report the wrong amounts and there is little the worker can do besides pay the taxes, interest and penalties owed on tips they might not be taking home.
My ex got caught up in it. The first year her employer reported her "estimated tips" to the IRS, it was based on a percentage of receipts assigned to her wait stations and according to her hours worked. At the start, the IRS sent a letter saying she owed about $400 in taxes on tips plus penalty and interest. We were filing jointly. The IRS told us to wait -- they will send us a bill for the amount owed. It took the IRS almost a year to send the bill, claiming they were waiting to provide her an opportunity to contest it if she kept records. Of course there were no records, because she was never informed the business was sending tip info to the feds until she received her W-2 after that tax year ended. in the year they took to send us a bill, the amount went from about $400 to over $875. I found out interest is calculated on a daily rate and applied to the entire outstanding balance. The penalty was more reasonable, but not when you combine the two.
So, it you want to talk "mess," taxing tips in the first place was a big one. How many tipped employees now keep records that fudge the numbers lower than actual to avoid taxes? I've known servers who only include tips written on credit card receipts. Cash goes straight into their pocket with no record.
Cash tips are on the honor system unless the business requires they be placed in a community jar and divided among the wait staff -- sometimes the cooks, too. If the tip is left after the check is paid, the business probably never knows the amount left or if any tip was left at all.
The process of tipping is itself messy. The IRS rules are also messy. The best way to avoid these inherent messes is to not tax any tips at all. When you consider the fact that tips are considered gifts for the employees with the amount (usually) determined by the giver, and that the IRS excludes gifts for taxation up to $19K per donor, there's no reason to tax them. So, if you happen to get a $100 tip from all your customers, and the total was $300K, there would be no tax since the gifts were from various tippers. Also, if anyone owes tax on a gift, it's the donor who may be trying to reducing their tax liability by gifting cash to relatives. If it's $19K or less, the recipient owes no tax on it.
The IRS is nothing if not a mess.