It’s a bit more messy than that in California even. Non competes are not forbidden, just generally unenforceable due to some other labor laws. So a lot of companies will still to this day have employees sign non-competes, and threaten them with legal action if they violate them.

They’d almost certainly lose, depending on circumstances, but the threat is enough to have a pretty strong chilling effect.

Well, I wouldn't take half my pay to not work. This is prime career time. The losses are huge? I could be compounding my income by working.

50% is an embarrassing amount. I'd accept 100% maybe.