Okay, but Consider The Following:
In a future dystopian world, children aren’t taught to write anymore. Everything’s done electronically and through technology, so there’s no need to learn how to write letters or characters since everything is typed with precision and clear-cut, readable font.
The only problem is that because all communication is done digitally, all communication can be tracked, investigated, and read.
Clearly, that would be a problem for any underground organizations or groups seeking to overthrow and rectify the current dystopian society. Any and all plots against the current government would be quickly stopped. In fact, the government probably has some kind of blacklist for certain phrases in the system which will alert the proper authorities if the phrase is used.
Sure, codewords are devised to evade these systems, but loopholes like those don’t last long. With as smart of AI operating the mass network, codewords for blacklisted words are discovered and blacklisted in the same contexts or from the same senders easily.
That’s where writing comes back into play. They quickly realize that going around the system rather than trying to play the system is much easier and more efficient. Great! Write notes and pass them by hand! Problem solved.
Everyone’s handwriting is godawful because no one learned how to write, much less neatly. So not only are the messages hieroglyphic in nature, it also takes ten times as long to compose a message before sending it off–not because they don’t know how to respond, but because they simply can’t write fast enough, and trying to make their writing be minimally decipherable further extends the time needed to make the message.
So not only are all these underground rebels passing notes back and forth like grade school children, but their handwriting also looks like the handwriting of a grade schooler’s.