Depends where you live. Most of the suburban and rural library I have been to are what you would expect with zero bums. My local ones are quasi co-working spaces with tons of telecommuters and even a coffee shop inside.
Rural yes. There are not enough shelters or public assistance to support the homeless population. I imaging your mileage may vary based on the specific metro area. I'm specifically referring to the southeast.
Also at least Chicago as well my cousin is a librarian there and constantly has stories about how her job is essentially running a halfway house.