Well, it depends on the application and context. I don't think a homeless person at the library is going to be booking a $1000-a-night room in downtown Los Angeles.

However, services that homeless people will be using should factor in their target audience (such as the homeless not having a phone at all, or maybe not one that's up to date even).

However, like it or not, having a modern up to date device is becoming essential for even rudimentary basic access to society. Whether that's right or wrong it's where we are.