The fundamental idea is that the employer is a corporation, and corporations exist through the laws defined by the government, which is (in theory) doing the wi

The fundamental idea is that the employer is a corporation, and corporations exist through the laws defined by the government, which is (in theory) doing the will of the people. So if the people, through the government, decree that an employer needs to pay for sick days, then that's how it would work. After all, the company exists through the combined effort of citizens of the government! and the company trades in money that is issued by the government, and managed by the government through taxes. Of course there's no reason the employer should have to pay directly. Why not have some sort of government program to cover people's illnesses? Or a new form of insurance? In the end, the public health improvement would be the same.