If the United States is to have more rapid economic growth, as most folks seem to want, then it needs more rapid productivity growth. Productivity growth is the key factor allowing rising living standards through time.
This is basically definitional. It means more output of goods and services per hour of work. It can allow us to have more stuff or work fewer hours and have the same stuff.
When we consider this simple logical point, it is bizarre that one of the attacks against Amazon is that it is costing jobs in retail. If Amazon is costing jobs in retail, it is increasing productivity in the sector. It is allowing us to get by fewer workers, meaning that workers can instead be available to do things like provide child care, install solar panels, or do many other useful things. Or, we can all work less.
Of course, they may not be the same workers and some people may get screwed in the process, but this is a larger problem of policy. For example, the Federal Reserve Board is quite deliberately trying to slow the rate of job creation by raising interest rates. Let me repeat that since it seems many people involved in policy debates somehow haven't noticed: the Federal Reserve Board is quite deliberately trying to slow the rate of job creation by raising interest rates.
If Amazon and other online sellers were not eliminating jobs in retail, the Fed would be raising interest rates faster in response to a more rapid rate of job creation. Insofar as increased productivity in retail is slowing the rate of job creation, it is allowing for jobs to be created in other sectors which would not otherwise exist.
It is also worth noting that productivity growth has been extraordinarily slow in the last decade, as in the opposite of fast. This is the main reason for the slow growth in the recovery. In other words, the economy's main problem has been too few job-killing robots.
(Yes, distribution is a problem and we should talk about things like patents and protectionism for doctors and other professionals, but let's keep it simple for now.)