I typically use "F100" or "F500" to refer to the space of all large corporations. This feels to me like a happy blend between explicit naming and including everyone with an LLC.
FAANG was coined by Jim Cramer, a stock pundit. It was the five biggest tech earners that year. Microsoft was flat which is why it wasn't there, while Netflix was the single biggest gainer in the S&P500 that year.
It has nothing to do with tech, salary, talent, or anything like it. It's purely based on stock growth in 2012/2013.