Reading for certs vs reading books at random topics you like

I used to read books at random like Stallings books on cryptography , Web Hacker's handbook etc
But this type of learning is basically a waste of time (you dont learn as much as you think that way).
I think studying for certs is a better way for learning.
So for people who like to study just go get some certs.With this way you get some feedback also about your progress.

books cryptography cybersecurity etc hacker handbook learn random topics waste web