Seattle wasn't as expensive back in the day and if I recall correctly, Bezos actually chose to move to seattle and start Amazon there for cost reasons (I think taxes were a big part of that). Moving an entire headquarters is expensive and did you forget about the HQ2 plan to expand elsewhere?
Seattle is still cheap for what it is tbh, a bunch of my friends have moved there and I feel like I’m getting completely fucking robbed by staying in Toronto (shouts out to covid hitting pandemic status just as I was preparing to job hunt).
Lower housings costs, significantly higher salary, much lower taxes, and better weather along with more interesting/nicer outdoorsy stuff makes Seattle probably my #1 choice for where I’d like to live right now.