Wage employment for reconstruction era blacks was different. After slavery was abolished, a number of replacement policies were put on to basically enable it under a different name. There has been a back and forth across the years of policies forcing blacks to unfair conditions only for courts or lawmakers to nope.
E.g. In Mississipi if a black man left a contract early to seek better wages elsewhere, they would have to forfeit already earned wages and could be arrested.
Surely, there are individuals for whom their employment status, then and now, are some form of extreme leverage not unlike slavery. However, Taleb is making a general statement across all wage employment, and that's pretty dickish. Plenty of people feel they have autonomy in their lives while working a job. Taleb asserting they don't is rude.