You covered a lot of ground there…
First, servers do like cash; however, as you noted, many times the kitchen staff - who are responsible for your food quality - are working for a cut of that. I don’t think there’s anything wrong with incentivizing the kitchen staff in that way.
I think they started taxing Social Security in 1983, but everyone doesn’t pay taxes on it, and there’s an odd point on the income spectrum where, as it becomes more taxed, it really gets egregious, then as you have a higher level of retirement income, you’re just paying normal taxes on it.
Illegal immigrants - if they’re being cut taxes - are no different from anyone else in how they spend their money. Sending money back home is not laundering. If they are evading taxes, that’s something else entirely.
All illegal immigrant money transfers pale in comparison to the Chinese. Over the last several years, they have taken over the money laundering industry, they actually launder money for the Mexicans now, and they control pot growing in the United States, both legal and illicit. It’s everywhere, in every state, and it has overwhelmed every other prior money laundering player.