Basically most people do not read, and most people here have no social life.
Libraries are for reading and socialising, so many users here have a really really hard time to imagine that someone might have some benefit from them.
Yeah but even if I didn't read, I would want any kids I own/any kids someone else owns to be able to access books, and even middle grade hardcover chapter books can be $30. I can't imagine paying even $10 for every single big flippy book they give the toddlers, that's gotta be at least a hundred a week just for the luxury of reading to the child for bed.
And that's far from all. Research, tool lending, children's activities, maker spaces, meetup spaces, study areas... My wife ran a sewing meetup at our library a few weeks ago; tons of people showed up with machines and made all kinds of stuff.
A good library is a focal point for a community.