My friend's wierd thoughts

So, I was just chillin' out, playing some Fallout 4, when out of no where my friend goes "Hey, want to know why slavery was good for us?" So, of course, I humor him. This is what he then said. "If slavery never existed, that'd mean that the pre-tension between blacks and europeans never existed So because of that, blacks are kept in Africa and no where else in the world and basically, with slaves working, they worked in the lucrative sugar trade industry, which was white gold and they took lots and lots of labor so thats why they brought in african slaves but if they didnt do that they'd have to rely on the natives aaaaaand, they died because... A they got murdered, B Disease so they had no natives to be slaves so they'd have to rely on europeans, which would be expensive AF why its expensive, because lots of people wouldnt want to go, so they'd have to pay them and not only that, they'd have to ship them nicely, because they are white, and back then, white is superior ' and sugar would not give them enough money to do that or any other crops which are intesive labor needed so basically, crops would have no source of income, so they'd rely on colonization, and fast forward a few years, the empires of the world are fighting in a huge colonization battle to colonize the world with blacks still out of society but the world would still be stuck back in the 1800s technologically because America never had its rise to power instead it just stayed a Brit. colony or even if it did break free, they'd still not create that big of a world power because there was almost no racial diversity everyone in the US was european and the Brits, Portuguese or Spanish was gonna advance if they already got a good system going so basically, all that we have today, would be thanks to slaves because at this point, we'd be technologically still in the 1800s" Take what you will, but I myself find this funny.