Let's for a moment make a thought experiment.
Everyone just magically has enough money to buy 'the basics', but can't use the money for anything else, in fact they never see the total.
What happens the the price of 'the basics' then? What happens when everyone can afford to not be wanting?
There are probably 'better' basics, for example penthouse apartments, but those will are all already above basic, so buying caviar or high end steak might be off the table.
What would happen if demand is just met?
The money would need to be spent anyway, these are basics. Not having spent it would result in what? More crime, more jail time, worse medical outcomes? All of that sounds like expense to the population at large, in the form of emergencies that use social safety nets.
I think the argument for UBI / BIG is that it identifies the root cause of the expenses and attempts to just fix the problem (by, for example, having a basic minimum of housing, or in the case of areas where housing costs too much; causing more housing to be built).