In my opinion, elders have a lot of valuable experience. The experience can help us to cross different obstacles in our lives. Sometimes, we can skip plenty of unnecessary moves when we chase our goals. We can get to destinations faster than others if we follow their advice or suggestions. They have already made mistakes and learnt lessons. They know how to finish things directly.
On the other hand, although books also contain loads of knowledge and experience from authors, it is very difficult to ask authors when you have problems. You have to solve problems by yourselves. No one guide you step by step.
All in all, elders can give you instruction and suggestion. They will guide you patiently. Books only provide knowledge and experience without any guidelines from authors.