Conversly, leave a tip on a credit card bill if you want to ensure that the entire tip is subject to any tip pool.
It also makes it so that my receipts, credit charge email alerts, and monthly bill all reconcile. Otherwise you can have a transcription error when the server or restaurant owner misreads (or mistypes) the manually written tip line of your receipt.
To make sure it reconciles correctly, make sure you fill out the Total line legibly/correctly, not the tip line. That's generally what systems have you input at cash out, and they calculate the tip amount from that difference. The vast majority of mistypes/misreads stem from the Total field being left blank and the manager does the math on the fly, or the customer didn't do the math right when they wrote in the Total (so they end up tipping $4.50 instead of $3.50, or $1.50 instead of $2.50)[1].
[1]Restaurant manager for two years.
Also, by leaving cash there's never any math involved either as the pre-tip total is the final total.
People actually working in restaurants have earned that money and can use it to better their lives. It's a moral crime to forcibly take the money from them.
I'm Canadian, so I could have more correctly written "CRA" instead of "IRS" - and on balance, I do believe my government spends the money on good things. Certainly there are parts I disagree with, but that's why I, you know, vote and stuff.
More importantly, I think a server who grosses $50,000 and a QA analyst who grosses $50,000 should end up paying the same amount in income taxes. The server shouldn't get a pass just because lots of his/her income comes in the form of tips.
That said, I think it's wrong to think that the government can invest money more wisely or efficiently than the people who have earned it can, and I think it's morally wrong to take money from people (like wait staff--note that doing this materially hurts their pursuit of their own goals and happiness) for government boondoggle.