Our libraries have all that stuff, and often that is what's attractive to homeless people. They may not be penniless or destitute: a lot of times, people have no home, but they have a cell phone to charge, and they have a few bucks to spend on restaurant food (because they can't purchase/store groceries or cook for themselves).

So all these creature comforts and amenities attract people of lower economic class. Often it's really nice to use a lab computer, set your phone down while it's charging, get on the Internet and do some job searches. If there's a café in your library, then you can stay all day without leaving.

Even people who do have homes may prefer the library during the day. If they have obnoxious roommates, abusive family members, no A/C or heating, whatever, they can come to the library and enjoy all that, courtesy of the taxpayers.