Nitpick, FAANG hasn't been around nearly long enough to have enough parents with workforce age children for this to be true. Especially not for them to have gone through recent (last 5-10 years) interview processes that people complain about.

I know some of the first Black software engineers at Facebook and none of them have kids (they're early 30s). The rest of it is true, people are discouraged both by bias in interviews and internal promotion/politics.