Are you mixing up gardening leave and non-competes?
In any case, I think above some level of compensation basically all crazy clauses that people agree to voluntarily should be fine as far as the law is concerned: there's no need to protect well-off people from themselves.
There might or might not be an argument that poor people need to be protected from themselves like little children, and thus that there should be some contracts they shouldn't be allowed to enter. (Just like we only allow some very carefully considered contracts for children to enter into. Eg buying candy is fine; but going into debt is not enforceable against them.)
In any case, I think above some level of compensation basically all crazy clauses that people agree to voluntarily should be fine as far as the law is concerned: there's no need to protect well-off people from themselves.
There might or might not be an argument that poor people need to be protected from themselves like little children, and thus that there should be some contracts they shouldn't be allowed to enter. (Just like we only allow some very carefully considered contracts for children to enter into. Eg buying candy is fine; but going into debt is not enforceable against them.)