Why Writing Japanese is So Complicated

Japanese has three types of scrips: hiragana, katakana, and kanji. And we use all of them when we write Japanese. But actually, you can write everything in Japanese only using hiragana or katakana. So why do we use all of them?

BEGIN Japanology - Hiragana

Hiragana (平仮名, ひらがな) is a Japanese syllabary, one basic component of the Japanese writing system, along with katakana, kanji, and in some cases rōmaji (the Latin-script alphabet). It is a phonetic lettering system. The word hiragana means "smooth kana"