I've started several companies over the years. And yes, I'd love to find and hire those underpaid overproductive workers. I'd hire one today if he/she could convince me I'd make back double her/his salary. I know quite a few businessmen who'd do the same.

I've never gotten a phone call inviting me to join the secret cartel of employers holding wages down. :-)

As an individual contributor, it's trivial for me to provide 2x my salary in revenue or margin for a business that knows what it's doing. If the business doesn't know what it's doing and it's willing to actually let me engage with customers, 10x becomes trivial. I don't believe I'm remotely unique in this either. Perhaps the issue is the "convince me" especially if there's ego about that state of the business that's in play.