For one thing, the places are shrinking because many of these industries are moving to other places in the U.S. I've cited an example here a number of times of a major plastics manufacturer not far from me that is in the final stages of closing down one of the largest industrial sites in the county.
The company is not "offshoring" anything. It's just an old plant that needs to be completely rebuilt anyway ... and rather than rebuild it they are consolidating five different plants around the U.S. into one giant new facility in Louisiana or Texas that they built for something like $1.2 billion.
Interestingly, one of the reasons the company chose the Gulf Coast site is that it offered something that they couldn't get around here: pipeline capacity. The industrial process they use involves some hazardous materials that were shipped into their local plant here on railroad tank cars. For safety and efficiency reasons they are moving to pipelines to transport those materials now ... and the local plant here is surrounded by towns filled with people who have been opposing every pipeline project on the books.
So when the time came for them to make a decision about the future of this plant, shutting it down was an easy decision to make.
What would industrial output be if we still had an electronics industry, a furniture industry, a textile industry, a replacement car parts industry, an air conditioning industry? I could go on and on.
Do you really think Americans would be buying more furniture, more electronics, more textiles, more car parts, and more air conditioners if we had those industries here?
This shows a complete lack of understanding of economics on your part. If the factories were still here then the factory workers would also be consumers, they would use services and this multiplier effect creates even more jobs. They would also pay taxes and the local small town goes on. THIS HOW AN INDUSTRIAL ECONOMY WORKS.