It's partly just that it's tradition, but there are also practical reasons: 1) Chinese characters are traditionally/historically written with a brush, not a mo

It's partly just that it's tradition, but there are also practical reasons: 1) Chinese characters are traditionally/historically written with a brush, not a modern pen or pencil. Because brushes don't create uniform lines, there is a connection between the specific series of movements and the final appearance of the character (sort of like calligraphy pens). Basically, inconsistent movements tend to produce inconsistent-looking characters, so an agreed-upon standard aids in legibility. 2) Various components (most notably the "radicals") reoccur across many characters. Having a (mostly) consistent set of rules for how each component is written and in which order aids memorization because you're not learning every new character "from scratch". 3) Stroke order affects how mechanically efficient it is to write the character, which can be a pretty big deal when some of the more complex characters are upwards of a dozen strokes.