I hope the guy is OK. It is not very safe to live in a car for many reasons. Getting to the bottom of why he is homeless and how the original poster can help should be the focus here.
America is a mix of Capitalism and Socialism. Neither is evil, but neither could work on its own. Is it likely that companies would collectively hire military, police, firemen, build roads, fund schools for a future educated work force, build ports, etc. for the common good if it were not required by the government? Unlikely, so we would not have those things. Then there would be no ability to do business because there would be no educated people with a safe place to life and safe passage to work. However, with those things Capitalism can thrive and people have jobs, pay taxes and keep the system running.
While unemployment is low, wages are low also. Wages have been roughly stagnant for 20 years in the US. This should not be the case in a "free market" as low supply and high demand should increase prices (wages in this case). There are a lot of people working hard and still struggling to meet their needs. This is a societal problem that will not be fixed by capitalists because it is not in their interest to do so. That is why it is incumbent on the people to correct it via government. Unfortunately, money buys elections. Money buys many of today's "news" sources also. Therefore there are many people who have been convinced that Capitalism is the only way and that the rich are benevolent givers of jobs. Those ideas have been paid to be on the airwaves for a long time. It is a bit more nuanced than that.