There is cause and effect, a single cause can have more than one effect !!
That people have been forced to move to the streets to live in cars, vans, and old motorhomes (and yes, some in tents) is an effect. That people in the interim housing programs that have been taken from living on the streets, are expected to transition to renting in 90 to 120 days, is way wild; since the cause of people forced to live on the streets has not been addressed !!
For this effect, people say that it is because there isn't enough low income housing. It is proposed here, that, that is not the cause, ... not enough low income housing is also an effect with the same cause as above !!
So what maybe the cause ? Management via city councils, counties and the state, have created an environment for corporations, many with stockholders, to build large (many units) luxurious rentals, for the purpose of big, really big profits to the corporations and their stockholders !! Therefore, some people will get rich, very rich more quickly every year, with ever increase rates. Of course it is very nice to live in a luxury rental, if you can afford it. But there are no incentives by cities to build lower income housing / rentals with smaller profits. In decades past, apartment rentals had smaller number of units, and not luxurious with pools, spas, gyms, and ...., and were not build / owned by corporations to extract ever increasing profits.
Since it is not likely, that this cause can be undone or walked back, then more and more people will be forced to street living. The cities, the counties, the state have to respond, by implementing a mechanism to create an environment, provide incentives, or they have to do it themselves, to build rental housing for those that cannot afford luxury rentals, to at least brake financially even, or financially self sustaining housing that takes the income from the rentals and reinvest in maintenance and beautification of the rental units, this can be done.

Pardon, but I will continue the comment above:
This 'new neighborhoods', they would not be an economic burden to the rest of the city residents. They have to, the city management, they must create this 'new neighborhoods'.
With the current wealth distribution unevenes, and the economic trends can cities really only have +$1 M neighborhoods, and only $3500 to $4500 per month rental neighborhoods ?? We need 'new neighborhoods' as per above for the ever increasing numbers of lower income citizens. And perhaps, organized parking neighborhoods with reasonable rents for motorhome, or vans, or cars living, not RV parks, since people are not there for recreation, or decent tiny home rental neighborhoods. These can be done.
For the billions of dollars that have been spent in our state, and continuing, sufficient 'new neighborhoods' could have been built for low income housing thru out every city in the bay area.