There is absolutely no way that a central system (even at the state or county level, if you're in the US) can surpass in allocative efficiency what an individual can do for themselves.
While I agree with you in principle, placing the burden on an entity far removed from the local context will always leave people underserved or forgotten entirely, in which case their instinct to survive will hurt the local business owners regardless of whether they would have helped voluntarily or not.
Unless it really is a true basic income.