[1787]

"human convention of written language" is a bit much. Stroke order is almost as important as what the actual strokes are in the definition of a Chinese character, for example. Of course unless you literally watch someone write you observe the characters after they're written, but the most predictive latent mental representation of a character does include an order component. I know this because I made the mistake of memorizing many characters almost like bitmaps and have had to go back and learn how to reliably write/read hand written characters.

[snowwrestler]

I don't know what to say other than that the entire purpose of written language is to carry information between people who aren't in a position to directly observe each other writing. (If they were, they could just talk and would not need to write.)

[1787]

There exist counterexamples in the broader world. Historically in the Sinosphere it was commonish that two people might share a command of written Classical Chinese but not really be able to speak to each other. For a modern example, consider the paper below: https://eric.ed.gov/?id=ED515291

[taeric]

Even learning English the stroke order can help considerably. Mostly it helps in just learning to write legibly, but that really is just a fancy way of saying it increases the accuracy of recognition. :)

I completely concede that it is possible to get the same results with other stroke orderings. However, there is a reason when teaching children how to write, we often get fairly prescriptive with stroke ordering, as well.