The quiet corner of a library may be doing work no visitor can see.

Some places matter for what they allow rather than what they display. In a quiet corner someone is studying their way out of a job they cannot stand, someone else is sheltering from a difficult house, and a third person is simply somewhere warm with no requirement to buy anything. None of that appears in a visitor count.

Protect the next shared quiet space you sit in, in the small ways available: the phone away, the conversation taken outside. If you have any say in whether such places survive, remember the people who cannot say what they use it for.