What is it about the fragrance of a flower that makes it a better flower than a flower that has no scent?

I believe that this question is asking about some kind of biological advantage that having a fragrance can give a flower vs. some kind of romantic advantage.
Flowers are part of a plant's reproductive strategy. In order for a plant to sexually reproduce, the pollen of that plant must be taken to another plant. Wind can do this, but wind affects the flower the same way regardless of having scent or not. The other way that pollen can be moved is through pollinators. A plant needs to be able to attract a pollinator, and two effective ways of doing this are through color and odor. Two flowers might be the same color and quite similar in shape; therefore, a pollinator might not be able to tell the difference between them (or isn't attracted to one more than the other). If the flower can add scent to its pollinator attraction strategy, the flower now has an adaptation that allows it to reproduce more frequently. This is good because it benefits the overall survival of the species. The scent of a flower can act like a homing beacon for insects or birds. This is especially useful for pollinators that work at night since color is next to useless at that time.