I completely agree. Where I lived at in Houston, trying to find a place to sit and study quietly was near impossible, which is something I certainly took for granted.
Libraries provide so much public good: giving the public internet access, allowing people to read classics and better themselves for free, and giving some quiet space for those wanting to study (and not have to pay for a $5 coffee).
Directly speaking, that's right. Indirectly, the latter statement is, of course, false in that libraries provide the means for anyone in society to raise their station and thus contribute more to GDP.
But I think you're making a good point that others are missing: The most valuable things in society are often things that aren't easily measured by straightforward means.
Libraries provide so much public good: giving the public internet access, allowing people to read classics and better themselves for free, and giving some quiet space for those wanting to study (and not have to pay for a $5 coffee).