I think the title and lede, "working for Microsoft cost me $200M" is intended to be provocative and encourage clicks on the article, while providing an interesting example of a "road not taken" in Garry's professional life. The dollar magnitude is unusual, but the feeling of regret is relatable to us all, even if you took the opposite bet that Garry did (e.g. turning down a LinkedIn or Coinbase offer in 2016 to work at a failed startup instead).
Since this article is on the top of HN today, I'd say Garry succeeded at sharing his personal anecdote.
On the content itself (startup vs. bigco), he is right about "you only can make a fraction of the value you create if you don't own equity" and "If you don't work on your dreams, someone will put you to work on theirs." But then it follows that everyone should start their own company if they are capable, or work for a bigco if they are not. The current SV labor market reflects this reality as well.
It's possible to sell some top-tier talent on taking less than 1% equity to work on your dreams, but they must really believe in the founder's vision and the founder's ability to provide a working environment that complements what the employee is not able to de-risk by themselves.