It might be cheaper to take the money and give it to everyone than build an elaborate means-testing system that requires taking far more information, a more complex computer system, more arguing over corner cases, and so on.

Straight handouts appear to be by far the most effective way of reducing poverty and its negative effects. It's rather like the War On Drugs; you can choose a system that moralises at people or one that improves their outcomes, but if you want to improve outcomes you have to give up moralising control.

It costs maybe 81 pounds a month to give you your 80 pounds. If it was means tested it would cost massively more per person you gave it to. In addition plenty of needy people would go without because they didn't know about it, or couldn't fill out the forms, or got arbitrarily sanctioned because their meeting with the job centre was on a day when the "advisor" hadn't met his sanctioning target