> All of these important cultural artifacts require maintenance.

This. Arabic users can complain about eg. Unicode not covering their writing in a suitable manner. And I (as a non-Arabic) can certainly see the problems described in the article.

But -going back to earlier days of computing- what stopped Arabic countries from devising a system that does that better than Unicode? (and covers other written languages like Hangul, Japanese or traditional Chinese, better than Unicode covers them)

Seems like that didn't happen? Either too few Arabic people cared, or solution(s) they came up with had shortcomings of their own & weren't implemented widely enough, or Unicode was good enough that few Arabic developers cared to go beyond that.

This has pretty much already happened for the older style of German cursive, called Kurrent. Partly also because the Nazis got rid of it.

https://en.wikipedia.org/wiki/Kurrent

Tons of old documents written in it, basically impossible to decipher for anyone that only learned to write "modern" cursive or even print.