Lower benefits, a proper national insurance system and higher taxes.
Although not many countries actually have a living wage, some have something like it in practice.
Governments in some countries recognise that everybody needs to live and have enough money to pay for a roof over their heads, heating and food, etc. even if they are unemployed, on maternity leave or just choose not to work and, therefore, pay much more generous benefits than the UK, although they don't have add-ons such as housing allowance and free school meals.
The idea is that people can keep the basic wage, but top it up with income or interest from savings without any penalty. Therefore, there's a much stronger incentive to work. It works something like the basic state pension and would work quite well with the rising pension age if it increased with age after, for example, 55. People could then be more flexible about their chosen retirement age.