The haves and the have nots have always been an issue but in places like CA with a million social programs it’s like a magnet for those in poverty.
I watched the one hour program about tent cities that popped up on YouTube a could of vids after the first one in the OP’s link and one thing I didn’t see were any kind of bathrooms or portapotties. Without those and the upkeep required of them; places like that have to smell really bad whenever the temps get up over 40 or 50 degrees. The other thing I didn’t see a lot of were cars and pickup trucks. Maybe they were at work when it was being filmed. In Cali it might be possible with the cost of rent and houses there.
I feel bad for those folks but sadly when they do get a few bucks in their pocket they immediately buy drugs and alcohol instead of saving up for a car or buy something they need. They just wait for things to simply be given to them because they know it will happen. People need to earn things to really appreciate them or be disabled and wish they could earn it.
A lot of homeless are not drug addicts, but that is a convenient label. Truth is that many hard workers know deep down they may wake up one day looking for a bush to sleep.
I staved off homelessness, into success, by being incredibly clever. The average family though is less than intelligent.
Some older folks just run out of jobs & money. Two years later, no job, is hard to recover from. Society is set up to favor bankrupting you.
And that makes people uncomfortable. So we call them vagrants.