I used to be like you. I stay on top of cpp con talks, I read Meyers and Andrescu's books and I had some fun side projects and I do fine at work, regular promotions, etc, but I did incredibly badly during interviews. I wasn't sure if it's some kind of IQ thing because I know people who can answer those CS questions without studying but I took the advice of some friends and I spent months grinding leetcode style questions. After a while something in my brain clicked and since then I've gotten a ton of job offers and worked at two FAANGs.