In the Americas, slavery was
More recent
Higher volume
A large proportion of the general population
Their descendents segregated even after freedom
Identity coming from such is a bigger issue.
That and being right out the window makes for more noticeability.
As vast acreage of sugar, tobacco, and cotton wasn't a thing in the Middle East, slavery was not as big there at any given time.
There are descendents of slaves in the ME, some in distinct communities.
Most simply integrated into the general society, as it isn't as big a deal with them and segregation unnecessary.