Data have shown time and time again that for every dollar spent on a public library the community return on investment is four $4 dollars. Public libraries are more efficient and effective the more they are used. The more a book is checked out the more people have enjoyed it or learned from it. Also, where else can you go without being forced to spend money? A lot of people can't afford these materials, just like they could not afford to pay for their own security (police) or put out fires by paying for private firefighters. Also, most libraries make up less than 5% of their municipal budgets, often closer to 1% in big cities. Seems like a good investment to me.

Homeless people are still people. The public library is one of the few places they are allowed without being judged. Yes, there are mental health issues and libraries are not meant to "manage" them. However, providing a means for no-cost life-long learning for everyone is essential to their mission. The idea of the public library you have is outdated. Try visiting your local library and see how they have changed.

You can check out books from the library and read them anywhere. Why do students need to read them in the library? If you are conducting certain research you need books as not everything is digitally available. Granted, most students are not doing this kind of thorough research.

That's true, but are they checking out books? :-) I just mean that from what I've seen, young people use libraries as a study space at least as much as they use them to obtain books (either for on-premises readng or for checkout).