> If Amazon succeeds in completely automating it's warehouses, who will see the bulk of that saved money, the customers or bezos?

The answer depends on whether Amazon is a monopoly. If everybody else who sells goods on the internet also automates their warehouses and customers choose the retailer with the lowest prices, they have to pass the savings on to the customer or the customer will buy from Walmart or some other competitor.

But "monopolies raise the cost of living" is a separate problem the solution to which is to get rid of monopolies, not to get rid of automation.