That's time consuming and expensive. If you found yourself in a situation where you're signing a non-compete out of desperation, you're lacking in both time and resources.
If you get stabbed don't the police arrest the person and, the state try and convict them? They don't leave it to the victim to mount a case, surely?
A proper legal system would provide sufficient reward to make it always worthwhile to challenge companies _clearly_ abusing their power in that way.
And even criminal trials end up in plea bargain settlements. The trial and deliberation isn't necessarily expected.
Sheesh.
And what would they threaten you with? Bring that lawsuit before a judge and they'd laugh you out of the building.
They'd probably have their corporate lawyer write a mean sounding letter, you'd ignore, no way anything happens beyond that.