Unfortunately, I don't believe there are many such places. If one is living in their tent, car, or similar situation, there are very few places where one is even allowed to exist peacefully without spending a few dollars, let alone take care of one's hygiene.

Libraries are one of the precious few places where one is not charged on entry or otherwise expected to buy something. Even public parks are increasingly hostile to the homeless, but often no real alternatives are offered. And I think that's a shame.

Downtown Seattle does not exactly resemble 99% of other places in the country.

Better a library than nowhere if it will help him find a job and escape homelessness.

There should be. Libraries have taken on that role because no one else will.