Yeah, I know, the services couldn't exist w/o the factories, and next we'll hear from the farmers that the factories couldn't exist w/o food, and then we'll hear from all the mothers-- we know that. What also got to know is that if a factory that does not have the right patents, efficiency studies, good transportation, a top notch sales force, and oh yes investors then it may or may not produce more than a few machines and it definitely won't stay in business for more than a month or two; but some other factory that does have those things will thrive.
We like to think that when we buy a car that the car is mostly made of steel, rubber, and plastic. Most folks don't realize that GM's largest single supplier isn't steel or rubber, it's insurance.
Everybody needs everybody but it is the manufacturer who pays- out of the wealth he produces. In extremis, no manufacturing = no pay for services. And this producer economy of manufacturers supports the consumer economy. Or government taxes and borrows wealth to support it like we do now.