Good question, not always; I suppose. The founders had quite a good share of stock which probably helped but ultimately it came down to vision.
My understanding was that Google didn’t really offer us a future plan, and the competitor they ended up acquiring (Wildfire) quickly disappeared — another fun little story is that Arielle Zuckerberg was working for Wildfire at the time, so she ended up at Google — while the Salesforce Marketing Cloud is stronger than ever after more acquisitions, even where the individual products disappeared.
All in all it still was extremely lucrative for founders and investors, the official number was $689m but there were also extra bonuses and employee retention incentives and such so the real number was higher.
I didn’t really gel with the FAANG style culture at the time so I left after I vested most of my stock, but I know some people made long careers out of it.