A bit off topic but, separate from Indian culture, the United States has a hidden caste system too that flows from antiquity and is given texture through American slavery. If your family was a slave or you look like a slave you are, unconscious in the minds of most, systemically bottom caste here. Sorry if it is an unsatisfying critique of America but its obvious. Go look at the wealth data, look who is thriving and…
Carry down that line of thought and you might fall into all sorts of nonsense. Note things like Pope Gregory (n?) saw a pair of slaves in a market in Rome in the n00s. These two were picked up from somewhere that would eventually become part of England/GB. He was told they were Angles. The story goes he quipped that they were "surely Angels" due to their physique and long blonde hair. Part of England is known as Anglia still and of course England itself is "Angleland".
It seems a bit odd that, that anecdote and play on words survives a good 1500 years during which time English has gone through three major stages (old/middle/modern). However you can easily posit from that story that Britons were also enslaved, if you very carefully define "Briton"!
Anyway, my point is that you can't really use terms like american slavery. History can't be stuffed into boxes like that with pejorative terms scattered like confetti.
The caste system being discussed here is nominally an indian sub continent thing and way older in origin than the slavery employed around C17th onwards with the horrendous triangle of trade.