This seems to be a strawman to me. I've never seen it argued that UBI should come with any kind of requirement that it be spent in certain ways, or that further monitoring would be required to ensure that people didn't do stupid things with it.

Yeah, some people will do with UBI what they do with their wages now: spend it on booze, gambling, video games, whatever their addiction of choice is.

But...that's not a problem that should be solved with strings on UBI, or anything like that. It's a problem that should be solved by trying destigmatize addiction, treat it as a disease, not a personal moral failing, and address the root causes that lead to it. Those things aren't easy, but that doesn't really matter for whether we should enact a UBI, because they're out of its scope.

However, if you reason through to some logical conclusions, it seems likely that, over time, a UBI that genuinely provides enough for people to live on, not in luxury but not in squalor, will tend to lead to these people having more opportunity to get themselves out of the negative spirals of addiction. It can give them hope. It can prevent many others from ending up in that situation to begin with.