If you want some numbers with actual sources, the median software engineer salary for a software engineer in the bay area is around $110-125K, according to Glassdoor[1] and Payscale[2]. You can argue about their methodology, but it's better than the usual "anecdote = average" logic that these HN salary experts employ. Even if equity added an additional 100% of salary (which I have never seen in my life) we're not even close to these oft-quoted $400K figures.
To you guys outside of SF. When you hear people throwing around these anonymously sourced salary figures you need to take them with an enormous grain of salt. These figures are fantasy land.
1: https://www.glassdoor.com/Salaries/san-francisco-software-en...
2: https://www.payscale.com/research/US/Job=Software_Engineer/S...