They always help a business and the other party signing it. If there was not mutual benefit, there would be no reason to sign the contract. The state may have

They always help a business and the other party signing it. If there was not mutual benefit, there would be no reason to sign the contract. The state may have concern if that mutual benefit is harmful to the rest of society. A medical doctor, for example, agreeing to not compete could see him no longer able to provide medical services, which could see a third-party to not receive the care they need. As such, the state may find a need to interject to protect the society (i.e. third-parties in need of medical care) it represents.