Specifically what I said was that they are worthless
until you get to see the cap table (which most startups will not show you.)Stocks are shares in a company. Imagine you have a box with money in it. And I tell you you get 4500 parts of this box. But I dont tell you how many parts there are total -- you see the numerator but not the denominator. In that situation it is impossible to discern the value of your 4500 parts since you dont know how many ways the money gets split.
It gets trickier, because cap tables also have liquidity preferences. So you can have 4500 parts of the box. And another person can have 4500 parts, but their 4500 might be worth a whole lot more than your 4500 because there are different classes of stocks. It isn't uncommon to have one class paid first, in whole or 1.x greater than whole before the next class gets paid.
https://en.wikipedia.org/wiki/Liquidation_preference
Oh, then there is the actual business -- there is tons of business risk. Even if the business does well, it may be in the red and the future of the company (and worth of your shares) are dependent on successive rounds of funding and their implied valuation. You get a down-round and you might be wiped out.
https://www.investopedia.com/terms/d/downround.asp
Even if everything gets well, depending on the classes of shares of decision-makers, you can end up in a situation where the founders/board might have an incentive to sell at just an amount where they make out well but employees get wiped out.
Case:
https://www.nytimes.com/2015/12/27/technology/when-a-unicorn...
Or Levandowski's side startup where the company got sold for just enough for Levandowski to make out golden
https://www.wired.com/story/god-is-a-bot-and-anthony-levando...
The Net-Net of all this is: stock options are not worthless, their worth is based on a formula with a dozen+ variables, almost none of which you know the values/ranges/distributions for -- and a formula where many combinations of theoretical inputs result in zero value.