How long before he is telling his workers that they can simply eat cake, when there is no bread.

Unions are a way to resolve long term labor disputes without large scale vandalism and homicide, because throughout history angry desperate men have always done desperate things. It's a lesson usually learned the hard way.

If unions didn't work, corporations wouldn't spend millions on anti-union propaganda annually.

The free market would simply make them useless.

But they aren't useless as we can tell from the capitalist class.