Books are tools to store information and share it with others. When we started writing things down we acquired a tool/technology to download our ideas and save them for later. Up until that point we had to rely on our (small) RAM memory and an unreliable hard drive to store and share information.
When Gutenberg introduced the printing press, it enabled us to scale the sharing of information with many orders of magnitude. More people were able to download more data from their brain and share it with the world.
When books became widespread, many people downloaded lots of data and were able to share it worldwide. However, most of this information sharing was still a one way thing, from author to reader.
The internet enabled us to have two way information sharing from many to many, all the time. Now we collectively download data from our minds onto the internet and share it with billions of others, continuously.
Books are just super early information technology.