You must have bad information because FAANG companies compete over hiring black software engineers. They want to get their numbers up and there aren’t many to hire.
Your sample size of five elite companies can't be taken as a serious attempt to describe the actual experience of black CS grads applying for jobs.
So that's 1.5% of all engineers. And that's being very generous. The real number is surely below 1%. No surprise that the most desirable companies hire the top 1%.
(Happy for someone to correct my numbers and the resulting percentage - it's based on a few Google searches).
Unless my numbers are way off, it's safe to say that over 99% of engineers in the world are not working at a FAANG. I stand by my claim that we should not be using what happens at FAANGs as reliable anecdotal evidence of the interview experience for most candidates.