Totally agree. I read way over 100 books a year, some of those are re-reads of books that have challenged me through the years, some are re hashes of the “fundamentals” as you call them, some have new ideas, some are just for the pleasure of reading. And yes, reading them has helped my success but it helps because I apply the knowledge, I can quote parts of a book and go deeper and explain them to someone who hasn’t read it. I know people who speed read books and can’t remember or explain a concept in the book.
One thing I have gained from reading so much is I can read faster and comprehend quicker. And since most of the books I read don’t make those lists or even the best sellers (some are old, some are hidden gems), I also enrich my vocabulary. People congratulate my English and vocabulary and say I know it better than native speakers, but most of that has been accumulated through reading (and it shows because I mispronounce words as to how I assume they may sound because I’ve only ever read them and not heard them).