What's your opinion on UK tipping in restaurants?

In the UK it's suggested you leave a 10 to 15% tip in restaurants, but there's no obligation to do so. This is a lot lower than what Americans are recommended to tip. Laws came in last year that forced employers to make sure staff actually got the tips.

The tables show average tip for a £100 bill. The percentage of population that won't tip. And tipping levels according to age.

I'd be interested to here the American view on these stats.
Whats your opinion on UK tipping in restaurants?
Whats your opinion on UK tipping in restaurants?
Whats your opinion on UK tipping in restaurants?
What's your opinion on UK tipping in restaurants?
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