Comment by lumost

Mix of the above. It’s not dissimilar to investment banking or other highly compensated field. You need to get to the top of the top firms. The top of the top comes from the population of peer companies. The population of peer companies come from the population of lesser peers and top schools.

It’s not as easy as some posters make it sound, but it’s still on the order of 20-50k engineers. If you wonder why these firms move faster than the rest of the industry, this is a major contributor.