Many people (including this comment) severely underestimate the sheer volume of information processed everyday by those staff level engineers in big techs.

Imagine that each day you need to review 1~2 design docs, read and reply tens of mails, attend at least 3 meetings and make non-negligible engineering decisions each, keep the lights on, manage and mentor some junior engineers. And write some code and design docs for your own projects upon all the crazy stacks of technical and procedural complexity.

Time is limited resource, so you cannot really have enough time to understand everything needed as scopes expand. You will eventually need to embrace ambiguities and uncertainties stemming from the complexity. And this needs more than just willingness and patience. Perhaps having some level of smartness can help, but this alone might not be sufficient though.

I mean, yes, it's not only intelligence, but also willingness to put up with bullshit, but "isn't smartness" is going too far. It IS taxing on brain.

Much "smartness" is a willingness to work hard, being able to read the room and being willing to put up with a lot of BS.

If you think FAANG is bad, just look at academia.

I'm not at a FAANG but am at a F500.

We're paid well because we have to shift gears a lot, learn a lot, fake-it-till-you-make it, and put up with oodles and oodles of BS.

From a technical standpoint a 16 year old could do my job. We're getting paid for patience and the ability to "code switch" in the socio-linguistic sense.