It is sad so many people are forced into that situation through no fault of their own. Some have a financial crisis, such as some major medical issue or a lost job, that puts them on the streets. What I find most sad about that is they don't have friends or family to help them out.
Others are there because of mental health issues. They simply cannot function in the structured life of a job and paying bills. Many would go to places that could help them, but unfortunately there just isn't enough places to help. What is available is full.
Some are addicts. They need help as well. Some would welcome the help to get clean and get back to living a more normal life. Others don't care. Like those with other mental illnesses there simply sin't enough help out there. Plus many people are too ashamed to seek help. Others just don't care. You can't help those who are not willing to help themselves.
Then there are those who actually like living that way. They like the freedom of responsibility. They like not having to worry about paying for housing or having a regular job. They find odd jobs when they need money. Others will beg. I am not big on those that beg. I don't carry much cash so I don't give to them. I will donate to places that help the homeless, such as shelters or food banks.