The correct answer to this open question is the following.
I suppose science fiction writers use this method to advance their stories because it is a magnificent way to use your imagination and conduct readers to never-before-seen places. Places where only can be accessed via the mind and the imagination. And that is fantastic.
Science fiction writers like French Jules Verne used his knack to take us to distant lands, or to space, or under the ocean, just using science fiction. He was a man before his time. He could predict the future in his novels. Something to admire.
Through the use of science fiction, you can write about otherwise controversial times such as other dimensions, ET's, UFOs, supernatural powers, and more.
I really cannot think of another good way writers might transport through time, as effective as science fiction.