No. Absolutely not. Lots of future tech comes from sci Fi fiction, which sometimes becomes real. Fiction about 'what if' scenarios give insight into how things could happen given certain events taking place, helping decision making for present events. Relationship books? I mean, those can be great examples of how healthy or unhealthy relationships work, and can help one identify the status of their own relationships. Fantasy books and sometimes a combination of the above, and all useful.

Nonfiction helps one understand what has happened. It gives context to the world we live in now, and what came before. Both are valuable, just in different ways. Reading anything helps your ability to empathize and think of alternative perspectives and is always useful.