250k is really pushing it.

I remember reading a Google earnings report that said they had 90k employees in total. Assuming Amazon/Microsoft to be larger and assuming Netflix to be smaller, we can take Google to be the average. Of that, even if 50% was engineering, we'd only have 250k FAANG engineers worldwide. In the US, I'd guesstimate ~100k.

Taking Google as the average is throwing off your numbers by an incredible amount. Amazon alone has more employees (around 540k as of the most recent reporting I can find) than you gave the entire group. Microsoft and Apple each account for more than Google as well.

Does the Amazon number include people working in logistics, delivery, and all that? I suspect that is huge portion of that number. Their engineering force is larger than Google's but not by much, I think (60-70k at best).

I wouldn't expect it includes those positions, as warehouse operations/logistics seems to be contracted out to other companies. Not sure, though.

Media reporting appears to suggest that number includes the supermarket chain they now own.