> 10^-9 odds of a startup making 10 billion
Intuitively those numbers feel wrong. theres 7bn people on this planet - and only a very tiny proportion might become tech entrepreneurs. So I think your "1 in a billion" chance of being successful is a bit high. Also, who said $10bn was successful? It is just 1 outcome of many...
Suppose, 10^-9 odds of a startup making 10 billion. Let's assume the other terms are negligible.
E_startup = ... + 10^-9 * 10^11 = 100$ E_faang = 10^-1 * 10^5 + 10-2 * 10^6 + ... >= 10^4