So, you've got a choice: $200K/year at bigco, or $120K/year + a one time payout of $2m when you sell your company in five year. Yes, slow and steady can win the race, but last I looked, $200K x5 is $1m. The solo founder will make $2.6m. Of course, there's no guarantee of any of this. The talented engineer could be caught up in layoffs at bigco, and the founder could go out of business or never sell. Usually, exits are done at a multiple of revenue, so it is not uncommon to sell a small company with $600-700K/year of revenue for 3-5x that amount.
BTW, raising tens of millions for one million in revenue doesn't happen that often.
Everyone I know who has worked at the top tech companies for 5 years has earned considerably more than the entire startup's revenue. I wasn't ever talking about the startup's equity value, but even if I was, they were earning more than the equity value they would receive too.
I've seen companies raise single digit millions and not even get close to $1M in revenue, over 5 years later. The result is founders have been diluted massively after a couple of down rounds. Meanwhile, preferred dividends are accruing year after year. The odds of a big payoff gets smaller and smaller the longer this goes on.
Odds are you'd make more money taking a job at BigCo, live like you only needed half what you're making, and invest that extra money into the public market. This isn't as fun though.
BTW, raising tens of millions for one million in revenue doesn't happen that often.