I think the parent comment was pretty clear that what's in it for workers is a bunch of money.
For as much as capitalists love free markets, they really hate the idea of employees selling their labor in a free market.
Employees should have the option to refuse the payment and go ahead and compete. Then it would be up to employers to make sure the offer is attractive enough that employees would want to take it. That's how a free market works.
Absolutely! But in reality NCs are mandatory parts of accepting employment to begin with, and it's a very broken power dynamic because I need this $150k job a hell of a lot more than my employer needs me as one additional person.
Additionally, a non-compete that only matches your existing salary isn't enough. There is a super strong compounding effect of
1. You haven't worked for two years, your value going back into the labor market could be much lower
2. Your income could have grown tremendously in those two years instead of forced to be the same
3. The net effect between 1 and 2 means you're not just behind the effect of 1 on its own, you're now actually super far behind
4. You now have two fewer years of your working life for your salary to compound
5. The savings you could have made in those years at a higher income level also aren't compounded as they would have been in your investment portfolio
For example, other Fund X has a huge short position in a company. The way that finance solves this is by paying employees to stay unemployed (and not take their potentially damaging information elsewhere).
There isn't really anything directly "in it" for workers, so paying them out for their time seems reasonable.