I bet this question has been asked again and again by so many bloggers (including myself), yet we are so busy with so many other things (creating content, marketing, coming up with post ideas… you name it) we tend to neglect to find answers for a simple SEO question like this.
So, I decided to get to the bottom of this and do a bit of research.
What do people say about blocking category pages?
From SEO perspective, category pages could potentially be duplicate content because they are essentially displaying excerpt of each post that are aggregated there.
On the other hand, if it is done right, it could bring you additional traffic according to the best answer I can across here.
In short, you should not block the category pages. Instead, do a bit of keyword research and plan your posts so that they are all aligned with that specific keyword.
Conclusion for blocking category pages of a blog
Category pages could be used to target certain keywords if the posts that are appearing on the category page are well aligned with the target keyword. Therefore you should not block category pages from indexing but rather you should optimize them.