Markets are, in many settings, self-organizing and 'efficient' in terms of maximizing the welfare of both buyers and sellers.
Here's a startling fact: in the 45 years since the introduction of the automated teller machine, those vending machines that dispense cash, the number of human bank tellers employed in the United States has roughly doubled, from about a quarter of a million to a half a million.
Economists have understood since the Victorian era that the main benefits of trade come from comparative advantage: the idea that people can specialize in what they're good at and then benefit from exchange. The principle is no more mysterious than specialization in the labor market.
Manufacturing value chains are global. Many U.S.-made goods have foreign components. Slapping on tariffs will raise prices and slow imports, but it will make us poorer and impede growth.
Our machines increasingly do our work for us. Why doesn't this make our labor redundant and our skills obsolete? Why are there still so many jobs?
History has suggested that the pessimists have been wrong time and time again.
