I suppose it depends on how you’d define “solved”. If we’re talking about basically eliminating homelessness, Cuba has done immense work in that regard. Say what you will about the Cuban government, but Cuba has a near-zero homeless population because the government has built a ton of housing and caps rent at 10% of individual income in that state-owned housing. Cuba is also a country with a tradition of multi-generational extended family homes, so there’s a greater chance that you’d be able to move in with a family member if you fell on hard times. Home ownership rate is around 85% compared to 65% in the US. All of this is nothing new, though, so it’s hard to say if it’s the answer to current issues of housing that’s largely driven by corporate greed, but it certainly sounds like it couldn’t hurt. Granted, I’ve seen people give examples of homes that are rather small and spartan, where the walls are made of bare cinderblock and generally aren’t very pretty, but that’s way better than being homeless even if some of the housing isn’t as nice as others. I’ve also examples of state-owned housing lived in by the same kinds of people, but are really quite nice as well. Whether the US government would ever do this, though, seems unlikely. Not at the scale we’d need and not for so cheap, anyway, especially not with Trump coming to office. I can’t really speak for the governments of other countries, however, and I’m no expert on Cuba either, so I could have gotten some things wrong. The US embargo to Cuba since the 90s also means that Cuba has had a more difficult time procuring building materials for the low-cost housing that’s helped so many, which has led to an increase in size and number for those extended family homes over the years.