If SF can figure out to automate away all of their poor service workers and then crack down on the homeless, then it would be truly a paradise for them eh?
This would require a level of fed-up-with-SF that I don't see in practice - like every other tech worker deciding to leave, and people in other industries too. But if that happened, yes: SF would become affordable and people with lower incomes could purchase houses there, and honestly that might not be such a bad outcome.
The city was once like this, after all - a place where people with low incomes, along with oddballs and misfits, could put down roots (buy houses) and live.
I've talked with residents who lived in SF back when it was a lower income city. Here's what they had to say.
Example: there used to be a time when you could find sporting good stores, tire repair shops, thrift shops, toy stores, and generally not-very-much-money making businesses in SF.
Those are all gone now - priced out.
If tech workers left, it's not like their office space would stay vacant. It would get repurposed. Those kinds of businesses would move back in.
They'd need service workers, so they'd get hired back.
And house prices, rent prices would drop.
If you think that's unrealistic, I would say: that's far more realistic than hoping for something that demonstrably is not going to happen - say, 500k new housing or apt units being built. That's not gonna happen.
If you want more affordable housing at any cost, no matter what, this is one actually realistic way to get there.
I'm just not sure it would, at least not until the long term. It's pretty challenging to make a retail store work on upper floors of an office building.