A thought about this: How are these even legally enforceable? If the employment is contingent upon this agreement, how can you make this claim that there are p

A thought about this: How are these even legally enforceable? If the employment is contingent upon this agreement, how can you make this claim that there are penalties for you after you leave or you're forced to leave? This is completely a one-sided contract that is detrimental to the person with less resources. It seems like to me, this contract no longer puts you "at-will." You're punished for walking away.