Simple example today in the US is welfare. The government prevents people from buying alcohol or cigarettes with their welfare money. Of course there are numerous work-arounds, but the point is that it happens today. Now extend that to the whole population, and the issue is considerable.

A very big point of UBI is to eliminate exactly the type of regulation because both of personal liberty reasons and, perhaps more importantly, it is a source of administrative inefficiency in the programs.

The development of the political consensus necessary to pass a UBI would be, exactly, a political rejection of the idea that such restrictions are desirable.

Trying to scaremonger against UBI with this as the supposed threat is nonsense, because it is, in effect, defending the status quo in which these kinds of restrictions are already imposed on people against a change which would remove them on the idea that somehow, in the distant future, those type of restrictions might be reimposed.