Well, some posted and informed me that it’s not universal. I knew some restaurants were doing it, and I knew the IRS had been hot on tip income for years, and it would make things more convenient for them, AND be unfair, so I assumed the two were connected.
It falls well below the gov't maximum for tax-free gifting. I almost never leave a tip on a credit card, I leave cash on the table. I worked hard for my money all my life, and know what it is like. If the service is good, I always tip over 20%, even if the food leaves something to be desired.