One of the selling points of unconditional cash transfers is that they wouldn’t be a disincentive to work. That instead they would help quality of life. And indeed, in high poverty contexts, they don’t disincentivize work. But this result suggests that in the US at least, they do cause people to work less. This is only one study in one context, so I wouldn’t consider anything “proven.” But, it is a big study and a very bad sign.