[nirnira]

people who've seen the place they lived their whole life slowly push them out, even though they're still needed there.

But they're clearly not still needed there - otherwise demand for their services would be high enough that they would be able to fetch a market price high enough to allow them to compete in the housing markets.

The big fishes need the small ones to survive

Let me ask a tough question: why do these big fishes need the small ones? What exactly makes the small ones so essential? To make coffee? To staff checkouts? If demand for these arguably location-limited services is so high, then a shortage of suitably qualified labourers will result in a price increase until demand and supply equilibrate. But I haven't heard of any protests by high-wage SF residents at their inability to procure the services they desire, so things seem to be ticking over. No ham-fisted government intervention necessary.

Your only problem here is if you think that successful people have some sort of obligation or self-interest to continually devolve income to support the less successful. But that's a new conversation.