[Objective]

Imo yes, very important but rules can be broken.

Why is it important? It sets the entire tone of how someone enters the first word/sentence of your story, and an idea of what to expect going in. Some expectations are needed to help the reader outside of punctuation, even as twisty as we tend to be with our approach to writing. I would even go as far as saying title is the most important in rap because there's so much information condensed from before. Having a referral point can untie a lot of knots that may be difficult to comprehend for the reader/s in question, having this in place is definitely a big + imo. So... 100%, yes! DO think about your titles.