I was responding directly to a comment referring to Staff Google engineers. So in response to your goalpost moving question, I guess the percent would be (total number of staff engineers or higher at Google) / (your random estimate of the total engineering population)
I’m sure we are all very impressed by your insider knowledge of the details of a tiny portion of the industry irrelevant to most engineers. For the rest of us Google Fellow or equivalent is a reasonable way to sum up the entire niche.
It's not equivalent, unless you think that getting a job at Google, Facebook, Microsoft, or any other reasonably large west-coast company is a "niche" that's completely out of reach for you. "Staff" is not some unattainable level that only a few people per company are lucky enough to break into.
