Depends on how open-minded and willing to learn one is. If you think you're hot stuff and couldn't possibly be a better lover than you are now, then no, there's no point in reading them. Once upon a time . . . an old girlfriend of mine learned how to have orgasms during coitus as a result of reading a sex book. A large percentage of women have much difficulty reaching orgasm through intercourse, and it's not a fault of poor performance. It has to do with positioning, circulation, muscle tension, etc.
Sex is a biological process.
Most people don't know the details. Nothing but good can be done from reading sex books, if they're good ones. Also, I'm ready to go again much quicker and more often. I feel energized. Learned it from a sex book.