Which is part of the reason for their compensation.
Did the first few factory workers and car design people at Ford become millionaires (in their equivalent dollars)? Probably not, but if you're the first engineer of a Twitter, Google, etc. it's not unreasonable to see your net worth to reach 7 figures, if not 8 figures. Early engineers are compensated just fine IMO, they are just taking a big gamble relative to the market (i.e. $500k annual salary at Google).