The basic idea behind income instead of housing/food is that individuals are better at figuring out their needs than the state.

Well in the US governments should do more to ensure cheap housing exists, and that groceries are available.

But providing it for free is less optimal than a basic income.

Either way it's a pretty direct tradeoff. Basic Housing and Basic Food would mean that a much smaller Basic Income would do a similar job.

Good point. As production technology improves alongside automation, bringing us closer towards a post-scarcity civilization, society will be able to make more guarantees, as they are materially trivial to create.

Yes, most developed countries have programs for affordable housing and food supplements. UBI helps with that as well.

This is what the military does. Of course, you’re expected to work.

Income Basic Allowance for Housing Basic Allowance for Sustenance