Amazon explicitly engineers this into the interview process via “bar raising”. You have to be better than the bottom half of people who hold the position to get hired. If Google is implicitly doing the same thing, I’d guess the same 40-60% that was mentioned in the thread.
I think most (entry to 5 years of experience at least) people who work at FAANG companies spend dedicated time studying for interviews. They also know exactly what their company is looking for - leadership principles for Amazon, for example. If you gave current FAANG engineers a month to prepare, I think 80% of them would reclaim their jobs. If you gave them no time to prepare, I think less 30% of them would reclaim their jobs.
The ability to solve contrived coding problems is a muscle that needs to be exercised, even when one does actual programming for their job every day. I'm guessing most people don't practice interviews when they aren't expecting to interview, so only a small percentage would retain enough to pass a loop.
