Oh, it's somewhat arbitrary, but Facebook was founded in 2004 and by 2010 no longer counts to me as a "startup". I suppose 2010 is still pre-IPO (2012) and therefore has a chance for advantageous stock grants.

(Not lost in all this: over the years the tax treatment of option grants has changed! It used to be a hugely advantageous way of giving employees something of value, and that's been eroded a lot.)

Get rich in the sense of "decent salary, and HODL the company stock", sure. Get rich in the sense of riding that startup VC wave, no.

Amazon had north of 100,000 employees by the time I joined in 2012. The "plucky startup" days were long gone, even if they did still tell the fable of the door desks at every orientation class