I think this is the crux of his argument. Of course there are outliers, but 90% of the time (I don't know the actual percentage, but I'd venture it's around there - if we're only talking about money I'd say 99.9%) someone will be happier if they go to a more established company.
And people are often disillusioned when their equity becomes worthless, because for years they were told that would be worth millions and they accepted low salaries because of it.
Of course sometimes it does work out great, and I'm happy that it did for you! But statistically, you are incredibly lucky.
Of the high-growth tech startups we're looking at, here's an analysis pointing towards 92% failure rate - https://s3.amazonaws.com/startupcompass-public/StartupGenome... - I suspect the real number is actually much higher if we're including seed stage companies.
Beyond that though, it's mostly me piecing together anecdotal evidence of disgruntled startup employees who left for larger companies and regret not joining immediately after college. There are of course plenty of people who join for the experience, for the smaller team sizes, the autonomy, etcetera. But I think my argument is largely driven by equity. Unless you'd happily except the job offer without the equity it's pretty hard to refute that people join startups because they want equity. And that equity is almost never worth it. If you aren't a single digit employee number at a company with a 10 digit exit, and this is still assuming you didn't get fucked by dilution because of asshole investors, the math just doesn't add up.
The odds of being in that cohort is much less than 1/1000, probably closer to 1/10000. It would take me a bit of effort to find a hard number on it (looking at total number of employees at large exits, find large companies that failed, approximate number of employees at various other startups) - but I actually know people that were employee #X at a company with a 10 digit exit who didn't get screwed by investors and they still would've been better off going to Google in terms of financial compensation.
Also I think a lot of it is ignorance. Many people at startups don't realize how much better it could be at a FAANG company because they've never worked there.
What's the amount of your salary? What's the value of your equity compensation? How much time do you get off?
(your benefits may not be as good as you think)