Ish. If you are just talking about that stick of gum or something else tiny that nobody cares about, sure, cash is easier. If you want to trace larger things, it gets a whole lot easier. Especially with modern AMA laws.

Homeless people should be offered homes and food. Not given petty cash to try and get these things. I'm open to the idea that cash is the best we can do today for that. But... that is a pretty weak reason. Housing and food stability are not won with petty cash.