Be careful. There's multiple aspects to a contract.

At the most adversarial, a contract is what you use as the basis for litigation, if it comes to a legal fight.

But a well written contract is meant to avoid costly litigation, by making clear what both parties expect from each other.

In practice, contracts are often boiler plate and lots of provisions do not apply, but would still be legally enforceable. While other expectations apply, but are not in the contract or are not enforceable.

To give a silly example: many of my employment contracts specified some pro-forma working hours like 8am to 5pm. That was never enforced.

But: if I had annoyed my employer in a way that the legally binding parts of the contract did not specify (eg by breaking an onerous clause that wasn't actually legally binding), they could have used those other clauses to annoy me. Or just fired me for officially unrelated reasons, or no official reason at all.

in the case of a non-compete, it doesn't matter because you are already not working for them and also not bound to not-compete

yes, it is discretionary, know your leverage and be able to afford it.

You have a point with a non-compete, but it's a matter of degree: there are certain obligations that persist after your employment, and some of them are legally binding, even if a non-compete ain't in your jurisdiction.

Just two posts above is an example of someone who got let go from their new job when they found that he signed a non-compete at his previous job. Easy enough to bounce back from in the right labor market, not so easy in others.