There is some bullshit that goes on here though. Many companies do not have a contract that you sign and consent to, they just try to back door it as fungible company policy - like the way social media companies get you to agree to new privacy policy and terms by your continued use.

Many companies put these IP and non-competition clauses into bonus award agreements. By accepting a bonus you agree to a bunch of terms and that’s where consideration comes in and makes it a real contract and legal. I have less of a problem with this arrangement than the back door approach.