Is it voluntary to buy social security? Companies help workers buy social security, but many are unwilling to buy it! Is this ok? Is the company responsible?

Social security is compulsory by the state and does not support the voluntary principle. Companies must be responsible for purchasing social security for employees, but there are two ways to pay insurance premiums. First, the company is responsible for payment, mainly for employees engaged in dangerous work; The other is shared by both parties, the company's contribution and the employee's contribution, mainly endowment insurance. It is wrong for the company to ask employees to pay for themselves. But most people who work now don't know this, so many factories say that the state requires to buy social security, forcing employees to buy it, but they have to pay for it themselves. Please be vigilant and don't spend money on unnecessary things.