Obviously this means one has to be earning that much for 15+ years.
Still, if you reach staff-level at 40 years old, you could have $25M at 55. That's pretty amazing. But that requires lots of luck. Most people never make it to staff-level. I never did.
Another thing: People at FAANGs usually ride the stock up and get way more than 7% per year. I'm embarrassed to say that I sold a lot of MSFT stock at $30 in 2011. Today (~15 years later) it is trading at $530.