A book with proper margins says a number of things. It says, we care about the page. It says, we care about the words. We care so much that we’re going to ensure the words and the page fall into harmony. We’re not going to squish the text to save money. Oh, no, we will not not rush and tuck words too far into the gutter.
A book with proper margins says, We respect you, Dear Reader, and also you, Dear Author, and you, too, Dear Book.
A wonderful essay by Craig Mod on book margins. And so much more.