The rustbelt, deep south, and Appalachia are not some beautiful, middle class paradises. They're full of towns littered with heroin and meth addicts subsidized by welfare and petty crime. You just don't see it or read about it because it's across thousands of small towns and not concentrated in major cities, where media also tends to live.
These places have a lot of violence, social issues, drug overdoses, etc. They may not have homelessness at the same level because housing is cheaper and in many cases involves a trailer or an old house in disrepair.