I'm not making any comments or judgements whatsoever on employees there, but doesn't Meta use the same terrible hiring practices that values so-called "leet" code style interviews? Such interviewing practices are bound to produce poor results, especially at the scale that Meta, Amazon, etc. do them at.
These two statements do not follow, why would "such interviewing practices [be] bound to produce poor results, especially at the scale that Meta, Amazon, etc. do them at?"
Thus, it is only natural that you may have many people in the organization and on teams who are poor fits, either technically, culturally, etc., because almost all of the "leet" code stuff is irrelevant to most real-world work. If it is relevant, then it is usually only a small portion of the job. This isn't a judgement on anything other than the hiring practice.
But like I said, I don't really know much about Meta's hiring process. It's possible that I'm misapplying this style of interview to them and misunderstood about if they actually use it. Amazon does, and I can confirm it was a miserable interview experience.
Meta's hiring bar is pretty high, though. Plenty of desirable people will stay because there's nowhere else to go that pays as well, and the "less competent" ones are likely still more competent than the industry average.
These elite companies have now laid off hundreds of thousands of people. The idea that there's enough "low performers" to throw in the garbage should be obsolete now, and reveals a sort of wishful thinking "all those other people who lost their jobs deserve it, but not me, it will never happen to me"