Let's look at it this way: Government just provides the essentials (what essentials consist of is to debate but still can be setup by an expert committee) and people can get whatever they want once they get a job (and thus reducing the aid they need).
Because some things won't be deemed essential. And now someone has to arbitrate that. And so the government is now making decisions about where you are allowed to live. What constitutes essential housing? Are you allowed to live in non-essential housing and "top up" or do you get stuck with what the expert committee has decided?
We have government-owned public housing in my country, and it has many flaws, in practice. Long wait-lists to get an apartment, no choice of where your apartment is, and little in the way of power to act should you need to move or have something fixed.
If they were given cash equivalent to the value of that housing on the market (a program we've been shifting towards but which lacks funding) then they can rent a house where they need it. Got a job? Move. Landlord is neglectful? Well, at the very least you can probably move.
There's a middle ground, of course. In the case of housing in particular, it might be reasonable to mandate a proportion of social assistance cash payments be spent on rent, should a person end up interacting with homelessness services. (But this is of course assuming you actually can rent anything with that... sometimes not.)
One issue we see here in Ireland is that there seems to be no path to create laws that force land developers to allocate sufficient space to affordable (they read "affordable" as "less profitable") housing. Since they have pockets deep enough to help their friends get elected, there is not much surprise such things tend to not happen. Ireland's ranked voting system is great for weeding out extremism, but doesn't work as well for preventing regulatory capture.
In general, I think people can more efficiently allocate their money than a central government planning group can. If an aid recipient wants to buy cigarettes or a drink with it, that’s not what I’d choose, but if they’re going to, I want them to do so as efficiently as possible.