I think most of practical basic income systems proposed don't actually go that far. I mean, theoretically the goal is to replace all welfare spending, maybe, but as said below, it may be hard to do practically, so most current proposals replace only portion of it, while leaving many targeted benefits intact. I don't feel currently informed enough to form opinion about whether this can work or not, so I'd be very curious about somebody trying it - preferably in some place where it won't hurt me if it fails in some unexpected way, like many social engineering projects had. Like in Japan :) Sorry, Japanese people, I know it's selfish from my side to want that. OTOH, if it works, you get a big win.