Except they won't be dead, they'll just be living very badly, and end up costing more to society due to using services (some study showed that a homeless person

Except they won't be dead, they'll just be living very badly, and end up costing more to society due to using services (some study showed that a homeless person in new york costs around $40k extra in services compared to "median" people... why not just hand the guy $40k?). People living on the edge end up costing more to society, it's an externality not taken enough into account in the labor market.