New Zealand doesn't really pay restaurant workers a living wage. Most waitstaff will be on minimum wage, or near minimum (~$16-17 per hour). The living wage in NZ is $20 per hour.

Australia has it better. Most waitstaff I know are on at least $20 per hour, with penalty rates for working after 10pm or working on Sunday.

That assumes one has a right to dictate how someone else will manage their private property.

Ideas like a mandatory "living wage", that while possibly well-intended, amount to coercive impositions that are rationalized by dogmatic self-righteousness, and end up having pretty severe negative unintended consequences.

They're in the same class of laws as those prohibiting prostitution and drug-use.

UK and most of Europe has to. America the Great is stuck in the social Stone Age.

UK legal position is more nuanced than that. Money-for-sex is generally legal, but on-street soliciting, two prostitutes sharing a flat, some forms of advertising, and many other aspects of the sex trade are crimes. So you may be legal, depending on what kind of sex work you're doing. Or you may be not. It isn't Amsterdam.