At low wages (effectively starvation wages in many cases) there is a huge incentive to show up for work.

With a UBI there is less incentive due to hunger but those same wages look much more attractive. There is still an incentive to work.

The money for the UBI does imply that profits go down, taxes go up (a mixture).

But importantly those workers, previously on the edge of starvation, will start consuming services initiating a virtuous cycle. That is the theory.

But a sensible housing policy (hello San Francisco) is very important or landlords will simply hover up all the surplus.