> Making an agreement you have no intention of adhering to is not ethical, regardless of whether the law backs you up or not.
Non-compete clauses are unethical. Adding non-enforceable clauses is unethical.
Both of the aforementioned points are made worse by the fact that the companies generally have more leverage + more ability to retain legal counsel, make it a lot worse, because that means that they most certainly knowingly do this.
I wouldn't even excuse myself for signing something like this while knowing of its non-enforceability.