The articles you've cited don't show a problem with "vacancies", but with mismanagement, lack of funding, and lack of sanitization/maintenance.
To add an independent voice, here's ChatGPT responding to "summarize this article in one paragraph", for each article you linked to:
> https://www.kqed.org/news/11668623/why-do-thousands-of-l-a-s...
The article discusses the significant problem of empty beds in Los Angeles County's homeless shelters, despite a large homeless population. Investigations reveal safety and sanitation issues in many shelters, such as bedbugs, rats, foul odors, and lax medical care. Half of the LAHSA shelters had 78 percent utilization. Homeless individuals cite issues like theft, harassment, and violence within shelters, prompting some to prefer living on the streets. There's no unified oversight system, and the is much room for improvement to ensure humane conditions in shelters.
https://www.sfchronicle.com/opinion/editorials/article/san-f...
Approximately 7,800 homeless people in San Francisco, 2,100 have been approved for subsidized housing, yet challenges persist in moving them indoors. The city cites issues such as a shortage of case managers, complicated paperwork, and resistance from the homeless to certain unit conditions. Although efforts have been made to address the problem, including a $62 million investment in case managers, the average wait time has increased to five months, a significant delay considering the program's annual budget of $356 million. The article calls for an in-depth audit of the permanent supportive housing program and urgent action to house homeless individuals promptly.
https://www.sandiegouniontribune.com/top-stories/story/2020-...
The article discusses California's Project Roomkey initiative, launched by Governor Gavin Newsom in April 2020 to lease 15,000 hotel rooms for homeless individuals during the COVID-19 pandemic. However, the program's progress has been slow, with only about half of the rooms occupied over a month into its implementation. Challenges include delays in preparing rooms for occupancy, a shortage of service providers, and difficulties in transitioning residents into permanent housing. While some counties, like Sacramento, have seen relative success, others, such as San Diego and Orange County, struggle to fill leased rooms. The initiative, funded by FEMA, targets homeless individuals aged 65 or older and those with health conditions susceptible to COVID-19, but the article raises concerns about the overall effectiveness and limited coverage of the program in addressing the state's homelessness crisis.