Answer:
They explained the unknown.
Explanation:
Myths were so popular thousands of years ago because people needed answers to the unknowns of the universe, and science could not yet give them those answers.
Today, myths are still popular because they are a type of fiction in which we can let our imaginations run wild. In much the same way as our ancestors, we enjoy fiction because of the vast amount of mysteries that still exist in the universe. Now, however, fiction is not meant to explain these unknowns, but rather to entertain because anything is possible in a multiverse.
Well this can vary, it depends what it's for. Usually you'll see 200-500 words, in the lower end this would be a bit over a page. But to answer your question, the most likely answer would be 3-5 pages.
To call it a day is to quit work and go home / to say the days work has been completed.