Very interesting post, Wroclaw, but why would such an life be better than heading back home ?
Many people don't go home out of fear. Or a belief that things can only get better.
I can only guess. Many people end up on the streets as a result of debt, problems at home, alcoholism, drugs. The usual negative things in life. I imagine that one has to dig deep into the soul to find the courage to admit to being a failure.
If you manage to find a way back to normality... home. Then you do it with nothing in your pockets and only the shirt on your back. You have to admit to yourself that you achieved nothing. This might be a very difficult thing for some people when their family had even moderate expectations of them. For some people putting things behind them might be impossible.
There are those of course who have no such problems. They will sieze the lifeline of advice, help and family. And I guess after a short time will fit straight back into society.
Some people will stay where they are... on the street. They find themselves in work and making money. Earnings might come from begging, casual work and in one or two cases full time work. Full time work would be something like Kitchen Porter.
As I've said there are plenty places to get a shower and keep clean. Some hotels have shower facilities for staff. Any work in a hotel or restaurant comes with a meal included.
At places like Lincoln's Inn Fields the toilets used to open early just so the homeless wouldn't soil the area and so they could get a wash.
It's also worth noting that there used to be regular police patrols in and around areas where the homeless gather. Another reason to feel safe.
A number of these people convince themselves that they are doing OK and so they stick with it. Others might use what they have, get onto some assisted housing list and improve their situation. Some are persuaded to do this by care/charity workers.
For those who managed to keep a bank account open it is possible to make money.
Anyone who thinks that you need an address to find work is wrong. Any address will do. No-one is going to check the address of someone doing a low-paid manual job. If you can get to work on time no-one will care. I've known some building workers who slept in the site cabin or even the building they were working on. In the later stages of a building project, with new fitted carpets, it's not such a bad place to be.
This is all based on what I knew twenty years ago. But I suppose some Poles would fit into the above catergories.