Libraries also have people who can help you find the particular information you want, or to understand it because of knowledge or language deficits. They offer a relatively safe and distraction-free place to absorb that information, which many lower-income people might not have at hime. They have works which haven't been made available online and probably never will be, often because of copyright. The list just goes on and on. Maybe the information you want and can use is available "almost literally free and instantly" but not everyone's as super privileged as you.