Depends on the book. Depends on if you’re going actually take an action suggested from the book. Depends on what you want to be ‘helped’ with.
For the first I find that most of the memoir related self-help books aren’t that useful. Others such as ‘The Success Principles’ are excellent. I’ve personally taken actions from that book often and have found that it’s helped me do more and be happier.
For the second you have to take actions. They can be small actions, but if you don’t change then the circumstances you live in won’t change. That’s just how the world is. If you never take action then reading the book was pointless.
For the third, perhaps you’re looking for help to become happier. The Success Principles might not help, but The Happiness Advantage would. Therefore the first book would be pointless to read, the second would be on point.