The major tech companies outsource stuff that matters - I mean, for 20 years at least - to contracted outside companies who pay 1/10th the amount to Americans in "flyover" country and even less to offshore employees.
They do this because SWE prima donnas will not do an adequate job for some things no matter how much you pay them. Like, oh, say, cleaning the office microwave.
So I guarantee you that you are overlooking most of the actual work "at" any given large tech corp.
Source: working for a BPO company with offices in Appalachia, Manila, and Uttar Pradesh, among others.