The thing is
"The law says it has to happen" doesn't mean it happens.
And the weaker labour protections are in your country, the more bosses can walk all over their employees.
In the US, with their so-called "at-will" employment system, you can be fired at any time for any reason, and if you need the job to like, live, you won't even bring up your legal rights.
Mind you even on countries where polling happens exclusively on Sunday (like mine!) there are other subtle ways The Poors ^tm^ are kept from enfranchisement. "Voting happens on a work day" is just one of the ways it happens in one of our world's oligarchies.
There's a book I heard about where the main character is immortal. Nevertheless at one point he pisses off some mafia dudes, and they nail him inside a barrel full of urine and throw him in the sea.