Why do authors use short, snappy sentences?

its quick, to the point, and grabs the readers interest-just like that!

Okay, thank you :)

Thankyou :)

Usually it is to grab the readers attention or draw them in at the build up to a big event. Or it could just be their own style of writing.

Drama. Dramatic effect. Tension. Pivotal moments in the plot. Contrast. Authors draw out long calmer moments by lengthening sentences, adding phrase after phrase until you begin to marvel at just how lovingly tender an expression about nothing but words can be - for words are our most valuable asset. Even the earliest humans realised this. Suddenly; quite suddenly, repetition of a key word can make you pay closer attention, and you become drawn into the plot even though it has nothing to tell you apart from thinkings about a better world. A place where people are valued for helping each other to learn how to make the world even better still. It is our ability to learn that sets us apart from other (known) life-forms. That is the gift of humanity’s genes. Hard to believe? Even after thousands of years, we’re still stuck on traditional beliefs. Beliefs are fine, we all need beliefs - even if we ignore them because that’s all they are. Some are useful, but most are ignored because they require a change in behaviour - and humans do not like being told how to behave. Tradtions are more tricky - they’re harder to give up than cigarettes. Unfortunately, the creators of older beliefs (and traditions) did not foresee a future need for the integration of new ideas, beliefs or traditions on an ongoing basis. Their vision was limited by the amount of information available at that time. So humanity wasted many centuries chasing its tail and killing lots of people who might otherwise have become smart enough to save everyone from further pain. Many people thought the only way to unite everyone into a peaceful society was to kill or subdue all who opposed any of the many different visions of what the future should be. That forces us to play a long and expensive game which no-one can win for very long. One day, someone will find a vision which all can agree to and work towards. One day, someone will work it all out. Should be interesting. But it has to be worked out soon, before our planet becomes unable to sustain us. Or we all lose.

it creates mystery, suspence.

it’s more convincing & adds to the effectivity of whatever s/he wants the reader to picture out..