Because three's company.
OR, to add depth to the story, there is the hero, the sidekick that sticks by him no matter what, and the traitor, that may or may not try to come back to redeem himself in the end.
Three is a common number in fairy tales, stories and superstitions.
Happily Ever After Fairy Tales for Every Child - 1995 Goldilocks and the Three Bears was released on: USA: 1997
Happily Ever After Fairy Tales for Every Child - 1995 Goldilocks and the Three Bears is rated/received certificates of: Australia:G
Some fairy tales set in England include "Jack and the Beanstalk," "Robin Hood," "The Three Little Pigs," and "The Little Mermaid." These tales often draw on English folklore and settings to craft their stories.
the three little pigs and the little red riding hood
Happily Ever After Fairy Tales for Every Child - 1995 The Three Little Pigs 6-1 was released on: USA: 22 June 1999
Mother Goose They are not only fairy tales but also nursery rhymes. (Like the three blind mice)
Some famous cooks in fairy tales include the Gingerbread Man, who escapes from the oven, and the Three Bears, who find their porridge eaten by Goldilocks. Additionally, the Evil Queen in Snow White is known for her poisoned apple.
The Ugly Duckling, The Tinder-Box, The Emperor's New Clothes,
The fairy tale you are referring to is likely "The Three Little Pigs," where three small pigs build houses out of straw, sticks, and bricks to protect themselves from the Big Bad Wolf. There are only three pigs in this story, not five.
Try comparing his tales to Oscar Wilde's The Happy Prince and Other Stories. They have similar themes and motifs (small bird symbolism, similar lessons taught, etc.) Is this what you were looking for?
"Three Blind Mice" is a nursery rhyme, not a fairy tale. It tells the story of three blind mice who run from a farmer's wife after she cuts off their tails with a carving knife. Nursery rhymes are short poems or songs for children, while fairy tales are longer stories with magical elements.