That is how it should work in theory, but not how it works in practice. In practice companies can use their better understanding of the true value/cost of non-c

That is how it should work in theory, but not how it works in practice. In practice companies can use their better understanding of the true value/cost of non-competes to exploit workers. If there exists a large pool of workers who are willing to sign non-competes because they are not well informed about them, than in order to get a job you will have to sign a non-compete (or move to CA).