So, that adds up to around $495K/year, or maybe $300K after tax. With $50K/year in expenses, you're left with $250K/year, or $1M over 4 years.
On the other hand, $100k is by no means the largest RSU grant you can get, so, basically, we have no damn idea. Overall it’s pretty silly to speculate about someone’s net worth unless they’re excited to talk about it.
But the larger point that high performing senior engineers at megacorps can make way more than people outside the megacorp world imagine is true and surprisingly contoversial on HN.
Also all those calculations are completely forgetting that money is a time-sensitive value. If invested wisely, the first $ from 4 years ago would be 1.7$ today if invested into a typical low cost SP500