In Canada, similar gentrification is also happening rapidly in Toronto/Vancouver. Detroitification happened on the Canadian east coast (when the fishing industry died). And we have better "social safety nets". I don't think social programs manage to keep cities alive or the same as they were, nor would the overall country benefit from trying harder to do so.
The main difference w/ Toronto vs SF is that Toronto has a liberal condo building policy so more affordable housing is being built by a (relatively) booming real estate industry. Whereas SF's property development growth has nowhere near reflected its population/income boom.
The problem in SF is there is no middle class or family housing being built. All these fancy new buildings going up are high margin 4k/mo rent and some percentage of section 8. There's nothing going up even in the range of 1800-2800 1 or 2BR places.
What would probably be reasonable is 1400/mo studio, 2000/mo 1BR, 2800/mo 2BR. What would be ideal is more like 1200/mo, 1700/mo, 2400/mo respectively. Yeah, that's still expensive, but it's a newer building and hopefully older buildings would be around 80% of that. But that's not going to happen.
Some additional policies like penalizing companies for letting new places be unrented for some amount of time, or allowing developers to (temporarily) displace SRO occupants while they demolish and rebuild higher density buildings in the Tenderloin could possibly help change behaviors towards increasing the supply of more modest housing, but that's not going to happen any time soon. In the meantime, the city is fine letting people do what they want at top as long as it benefits the people at the bottom, with no plans to do anything for people in between.
And Atlantic Canadian cities are still great places to live because Canada has invested in social safety nets, sane urban development, and not abandoning entire cities. 'Detroitification' is a not-even-wrong way to describe how any population centre in Atlantic Canada has fared.
I could be wrong here, but I thought much of SF is considered "historic district" or something, therefore new, more dense housing is not being build, thus rents rise like crazy?
I don't think he's wrong. All of the new development seems to be along Market (hell in a one mile stretch of Market near my house, there are THREE huge residential developments going up); i.e., you don't see any new high-rise developments going up in the Mission district (which I believe is designated "historic").
The main difference w/ Toronto vs SF is that Toronto has a liberal condo building policy so more affordable housing is being built by a (relatively) booming real estate industry. Whereas SF's property development growth has nowhere near reflected its population/income boom.