If there were no social safety net we would be back in the Gilded Age of the 19th century when industrialists with their "free market", laissez-faire capitalism worked their employees for 12 hours daily, if not more, for peanuts. Until socialists began organizing labor unions, workers in this country had little rights and worked under dismal conditions. Social Security, unemployment insurance, the forty-hour work week, minimum wage, overtime pay, sick leave, Medicare, and Medicaid, all contribute to the sustainability of market capitalism.
Everything can't be commodified or privatized. Everything isn't a product or item to be sold in a market.