They already live on the bare minimum, but they have to clean toilets to get it. Now the government says you can live on the bare minimum, but you do not have to clean toilets.
So now you have to raise wages to entice people to clean toilets.
You are correct that it is not the exact same situation, but I think there would be even more disruption of the same kind the more you increase the government assistance.
Or so now people doing even more distasteful and/or lower-paid work outside of the formal economy because it can stack with means tested benefits can afford to clean toilets for low wages in the formal economy because it stacks with the now-unconditional benefits. Conjecture as to which effect dominates based on behavior with additional means-tested benefits is on extremely shaky ground.
But my conjecture would be we might see lower wages for desirable work, but higher wages for undesirable work.
Giving people money that you take away if they work dissuades them from taking jobs, especially jobs that net them the same or less than they get without working.
That doesn’t really prove anything about how giving people money that you don’t take away if they work effects their willingness to work.