Yes, I am talking specifically about slavery in the Americas. That's where I am. That's where I see the aftermath of slavery affecting my Black neighbors and coworkers.
Race is not based entirely on skin color. I've seen Black people whose skin is no darker than mine, or even lighter. They are considered Black because they have the hair texture and facial features. And because their family is Black and their culture is Black.
For example, Michael Jackson's kids are considred Black even though they look whiter than me, because their legal father is Black and they grew up in Black culture. Beyonce is considered Black even though she's about the same color as me, because she grew up in Black culture and her hair texture and facial features are Black.
On the other hand I am considered white even though I get pretty dark in the summer and my features suggest some Native heritage. Even though we are mixed, my branch of the family has the right skin tone and other features that they can get away with saying they're white. I have cousins who are definitely not white, and I was never permitted to meet these cousins while growing up. Because my branch of the family was allowed to a good education, to accumulate wealth, to decent health care, and to escape harsh penalties for various infractions, I'm better off than these cousins.
The Black people here in the USA are, for the most part, descendants of slavery. For hundreds of years, only the strongest and most compliant were allowed to live. Enslaved people were often killed in their prime over minor infractions. Thjey were stripped of their names languages and cultures. Well into the 20th century they were deprived of various civil liberties that white people take for granted. They were not allowed to accumulate wealth for centuries. They did not see themselves in the media until fairly recently, and usually they were shown as entertainers, criminals, and domestic servants. Even to this day, Black people with ethnic names often get their resumes thrown away. The difference in various outcomes -- health, educational, economic, the criminal justice system, etc -- are well documented.
In view of all this, Black people in the USA are at a serious disadvantage even to this day. The decent thing to do is to recognize this and challenge this. And to have empathy and respect for a people who have been repressed in so many ways yet still stand proud. This is a tribute to the strength of their culture. Black families stand together, they don't usually throw away a child because the child doesn't suit their expectations.
I know every people have been enslaved at one time or another. But generational chattel slavery here in the Americas is very different from other forms of slavery experienced at various times and places by different people. I have explained all this. We white people can usually ignore race if we want to. But if a Black person tries to forget about race in the USA, someone will quickly remind them and put them back in their place.
You still havn't addressed other social constructs -- except gender roles based on biology. If you ignore race, do you also ignore the economy, workplace hierarchies, social conventions, etc? Do you talk to your boss the way you talk to the janitor? When in college, did you extend equal deference to your college dean and to a struggling freshman classmate? Do you think money is just meaningless pieces of paper or numbers in a database? These are all social constructs yet they impact our lives. If you're going to say race doesn't matter because it's a social constrcut, do you say the same thing about wealth, social status, social conventions, law, etc?
You can believe what you want to believe. Maybe you don't get to see what I see -- my Black neighbors struggling every day and putting up with all sorts of indignities. I've done my best to explain how race impacts people's lives and don't care to repeat myself. If you still refuse to see that Black people are at a disadvantage and that it behooves all of us to recognize and remedy this situation, I have nothing more to say to you.