The situation is that many, many employers make signing one of these a de facto requirement for employments, and they are widely known / believed to be unenforceable, but you still default to being on the hook for your own legal defense if a company that has otherwise idle full-time lawyers on their payroll and someone high enough decides they don't like that you and a bunch of other people quit. They weather that fight better then you and your startup will.

I worked at an SaaS offering for market research surveys that was threatened with a lawsuit because we hired a software engineer who used to work phones in a call center that specialized in polling people. He signed the non-compete contract, obviously, but the point was to discourage him and other people from quitting, or their potential employers from hiring them.

Have you read one of these agreements? They're vague and defer all the important details to litigation.

Binding arbitration unless you opt out.

Yes, terrorize.

The idea is to make illegal lawsuits against people who broke no laws, so as to set an example for other people who are thinking about quiting.