Only when it has to. Nobody likes change.
Apple's going to be here for a while, they can afford the salaries people are demanding to be here.
The trend is already clear and accelerating for smaller firms. No startups can afford to hire here on a 500k seed. You'd be paying 200k/head all-in, you can't even run a 4-person company 18 months on that.
The bigcos will be slow and conservative like they are with everything. But change is already very obviously underway.
"Socioeconomically it's a city that is (was?) poised to become an "alpha global city," but it's possible that the NIMBY-driven excessive and premature housing cost explosion has destroyed that. I already feel like a lot of what made SF great has been driven away."
I completely sympathize, but here's the thing: now that I've lived in a number of different cities, it's become obvious to me just how comically limited San Francisco actually is. If you go to London, Hong Kong, Tokyo, Paris...you see these massive, sprawling cities with incredible transit systems and infrastructure. SF is a dinky little geographical backwater. It's landlocked (i.e. "supply limited"), with terrible transit and worse traffic. It's not a place that wants to be a global mega city, nor could it be one if it wanted to be.
I firmly believe that the real solution to the acute housing crisis in SF is other half of the demand equation: eventually, the tech industry is going to come to its senses and begin relocating. It has to happen.