Do you automatically assign credibility because they work at a FAANG? That introduces a bias where you assume someone is smart until they prove otherwise where you might assume the average McD worker isn't until the prove otherwise.
We do it on here where we assume a higher level of conversation compared to a facebook post so we leave a better message which reenforces the standard.
Thinking slowly and only in a simple way.
I have met brilliant people who do crazy things due to strange behavior patterns and emotional problem but that's different to being dumb.