What slave owners? Are you suggesting that we dig up 150 yr old graves? Or that we invade Saudi Arabia and get those modern-day slave owners?

Given the plain fact that in the modern world property can be fractionalized so that I own 5% of A or 1200 shares of B, and also that according to most leftists the government is owed some large fraction of my economic output, are you suggesting decapitating government officials and tax revenue collectors for keeping me as a partial slave?

How free is a Chinese factory worker to quit and go find a job elsewhere?

When Cuba rents its medical doctors abroad to foreign countries (usually in South America), how is that not slavery?