That argument is rather ignorant. I really hope you’re being facetious, intentionally obtuse, or “playing liberal” just to get a reaction.
The relationship between employed and employer is voluntary.
If you want to sell the products of your labor for more, sell them directly, IF YOU CAN.
The relationship of slavery, be it traditional slavery, or government imposed slavery, and is imposed by force. Big difference.
Your points are all valid and yes, i was playing liberal’s ... er, I mean Devil’s ... advocate. However, the moral argument against redistribution must nessarily ddress the “labor theory of capital” that formed Marx’s core condemnation of capitalism. Your labor is exploited by an employer to add value to materials. The product is then sold for more than the cost of the materials and labor and the employer captures the excess as profit (capital). While any employee’s participation may be voluntary, his participation in the capitalist system is not. Don’t participate and you starve to death.
One key difference between redistributionist slavery and capitalism is the freedom of the former to chart one’s own course and to freely determine who benefits from the “exploitation.” That beneficiary can be the state, an employer, or oneself. Redistributionism only allows the benefits to accrue to the collective — the state.