Both things can be true. That fact is that some groups that were discriminated against now thrive, and some don't (even after trillions of dollars in public spending). That is why cognitive testing is helpful at figuring out what is going on.

New ideas, such as the US was "founded on enslaved Black people" really only gained attention the last few years because of our inability to solve the gaps. People wanted an explanation, so the past had to be retconned. The other Anglo colonies - Canada, Australia, New Zealand - never had slavery and ended up about as well off as the US.