Why are dragonfly's abdomens so long?

The first reason could be that natural selection favors characteristics that helps an organism survive. So the long abdomen must be important for a dragonfly/damselfly survival. The abdomen of a dragonfly is segmented. It usually has ten to eleven segments and clasping organs are found at its tip. These organs are harmless and the organs are actually reproductive organs. They are only used for mating and egg-laying purposes, the organs are often misunderstood by people to be stingers. So I believe dragonflies have long abdomen for because it makes it easier for them to mate in flight. Let's suppose all the dragonflies lost their long abdomen, since they lost their long abdomen they need to find another way to mate. If they don't find another for mating they will die. So long abdomens are important for mating if they don't have them they can't mate.