Anyway, joking aside, social democracies as seen in i.e. northern Europe and perhaps Canada are hardly bastions of slavery.
They're also not socialist per se, since, generally, the means of production are still more or less privately owned.
I don't think of Canada's system as all that different from that in the U.S. Taxes are a bit higher and they have a single payer healthcare system. Are there any other major differences?
In fact, slavery was mostly practised by capitalists, as it was the ultimate low cost labour and desired by large scale land owners and maybe industrialists, not by communist collectives.
I have friends who grew up under communism. From their descriptions, I don't think they'd appreciate the distinction.
And the USA was rather guilty of using it, yet I don't think anyone is looking back to pre-civil war USA and thinking, "socialism!"
Fair enough, but that's because socialism (and I mean full frontal socialism, not a welfare state) is a subset of slavery, not a synonym for it.