The fact that an old not-very-technical book is still considered great doesn’t necessarily mean that the field hasn’t progressed, it could just mean that the book did a good job of presenting ideas that are still considered important today and that the book was important historically in the development of the field. Books which are recommended as an introduction to a field (often to non-specialists) don’t need to contain the latest research results or in-depth data analysis.
The fact that an old not-very-technical book is still considered great doesn’t necessarily mean that the field hasn’t progressed, it could just mean that the book did a good job of presenting ideas that are still considered important today and that the book was important historically in the development of the field. Books which are recommended as an introduction to a field (often to non-specialists) don’t need to contain the latest research results or in-depth data analysis.