I think what the OP intends is its size and diversity of the talent pool. Obviously, there are so many smart engineers outside FAANG, but it's also true that having world-class experts on cryptography, networking, distributed system, web technologies, machine learning, microprocessor, compiler etc etc... in a single company is something very rare.
I work at a FAAG-adjacent and the single most valuable thing for me personally is being able to hang out in the Slack channel where all the old timers idle. If I need context on something and nobody on my team knows, 9 times out of 10 I can ask there and someone will at least point me in the right direction.