It's a little extreme to say they have no value. It marginally helps an individual manager to know that their employees can't move. And if an employee wants to negotiate higher salary in return for signing a non-compete, who is to say that they legally can't do that? (Everyone knows that Bridgewater aggressively pursues onerous non-competes, but employees can retire young as a result if they stick around)
From a macro level, non-competes are awful. The economy as a whole does much better (is more productive) when the best labor is free to chase the most productive uses of capital. (And vice versa) Successful companies are constrained by the existence of non-competes, because they have a reduced pool of employees to hire. They may still do them for their own employees, but they can't take the step without everyone else taking it too. (A variation of prisoner's dilemma)
I'm generally a small-government low-regulation person, but this may be an instance where companies need to be nudged as a group to accept something that will help them in aggregate.
From a macro level, non-competes are awful. The economy as a whole does much better (is more productive) when the best labor is free to chase the most productive uses of capital. (And vice versa) Successful companies are constrained by the existence of non-competes, because they have a reduced pool of employees to hire. They may still do them for their own employees, but they can't take the step without everyone else taking it too. (A variation of prisoner's dilemma)
I'm generally a small-government low-regulation person, but this may be an instance where companies need to be nudged as a group to accept something that will help them in aggregate.