Why don't American vagrants work?

In fact, it's not that they don't want to find a job, but that they can't find a job. The United States is a country with a large immigrant population. A large number of stowaways come to the United States every year, but because some people can't find suitable jobs, they will become homeless. Compared with the work in the United States, most of them need to be verified. Even the workers on the construction site have technical certificates, so for various reasons, these tramps can only wander in the streets. However, some vagrancy is caused by bankruptcy. Since then, it has never recovered, and there are not a few such tramps, so it is inevitable that there will be such groups in any country.