There will eventually be a price point at which the cost of buying and maintaining machines is more expensive than human labor. The problem is those competitive wages are extremely low, measured in pennies an hour. (Mechanical Turk is a great example)
Today's minimum wage workers may eventually end up working illegally or flooding "gig economy" 1099 roles - driving their collective value in those markets down to wages less than a dollar an hour.
Without a strategy like Basic Income, our cushy Western living standards are going to be at a real crossroads soon. We're about to turn a good chunk of the Western world into Bangladesh