There are many obstacles to ending homelessness.
The most fundamental one is the nature of our market-based economy, which has created an extreme polarization of wealth and poverty. A new study by the RAND Corporation shows that over the past forty years the wealthiest one percent of Americans has taken $50 trillion from the bottom ninety percent.
Out of this inequality new corporate empires have emerged built on rental housing. One such corporation owns 70,000 units, another owns 500,000. This gives them unchecked power to increase rents and allows them to create financial instruments (derivatives) based on their properties, as was dramatized in the movie The Big Short. They have little incentive to make housing affordable since they make money from the derivatives that are based upon your house or apartment even if you can't make your monthly payment.
These corporate landlords do more than just sit around and count their money. They are very politically active--collectively they have given $368,000 to No on Prop 21, a movement sponsored by the California Apartment Association which seeks to defeat a measure on the November ballot that would institute statewide rent control.
The LA Times recently described billionaire Geoffrey Palmer of Beverly Hills as "a real estate developer whose many projects include downtown Los Angeles apartments." Those apartments are an arrow of gentrification aimed squarely at the homeless residents of downtown's Skid Row. Palmer is the single biggest contributor to Donald Trump's 2020 campaign, kicking in $6,405,000.
Paying the rent or mortgage so you can avoid homelessness is difficult because of a lack of jobs, specifically good-paying jobs. Keeping a roof over your head is so difficult that some teaching assistants at the University of California have turned to prostitution to make the rent.