Firstly, I said rarely, not never and secondly, it could be argued that actually, whether by design or happy coincidence, the usual suspects did benefit from some of your examples; no point in having a large section of unpaid labour in a predominantly agrarian economy when, as in the U.S., an ever-expanding industrial revolution needs low-paid labour to buy goods and services. Equally, no point in having 50% of your population not emancipated when, unless the ability to vote radically changes anything, letting them vote is a progressive, P.R. coup, much like the adoption of identity politics today. Torches of freedom!