Most startups, by a large margin, fail either outright or equity wise (ie: sell for less than was put in). Many more sell for only a moderate amount which gives

Most startups, by a large margin, fail either outright or equity wise (ie: sell for less than was put in). Many more sell for only a moderate amount which gives a relatively small equity payout (after dilution, etc.). The average compensation of employees at other similar companies was probably lower once you account for all that. You can't judge the outcome of buying lottery tickets by only looking at the winners.