I always found the idea interesting, at the condition that we suppress all other forms of benefits. It is a simple and elegant way to solve the welfare trap and it also would be easier and cheaper to manage than the layers of benefits from various gvt agencies.

To me there are only two real risks. First the idea that this will lead more people to stop working instead of less, which would be counterproductive. And I find it worrying that the counter-argument is "people are working too hard anyway". It is impossible to guess what would happen but as all former communist countries know, it is not fun to have grand economic ideas experimented on a live population.

The second risk is that this could work in a closed society like Japan. But most western countries have mass immigration and such a system wouldn't survive very long the abuse it would inevitably trigger in an open society.