Yeah, it's already common to not tip anyway. Sometimes I tip, sometimes I don't (though when I do, I'm more generous than the standard 10%).

FYI: 10% isn't standard: 15% is standard, 20% is good, and 25% or more is for great service.

Those are the norms in the United States, which has a tipping culture that is more or less unique compared to other countries.

In the UK, 10% is standard and entirely optional. 15-20+ is if you're feeling super generous.

Yes, although it's also common in the UK for restaurants of any level to add 10% to the bill for larger groups of perhaps 6+ or 8+ people in a way that is clearly not meant to be optional.

I never quite understand people who always pay 10% for service here, though. If I have received good service, I will tip perhaps 15% or more, partly to reward the good work financially and partly simply because it shows that I appreciated their efforts and encourages similar behaviour in future. Likewise, I will drop a tip to 5% or even not leave anything at all if service has been poor. In a happy coincidence, this means I tend to be regarded as a good tipper in the kind of place I want to go back to, and a poor tipper only where it doesn't matter. :-)

I also only ever tip in cash, directly into the hands of the waiting staff I've been served by. What they choose to do with it after that is up to them, but you'll never catch me adding some arbitrary amount of "service" onto a bill that's going to be paid on a card machine and go straight into the hands of the management.

That's standard in the USA. In the UK it is not standard, however 4 weeks minimum paid vacation (and about 8 days paid public holidays) are standard. Different countries.

(in the US, not Europe)