How to prevent Hangul phoneme separation when sending files from Apple devices to non-Apple platforms?

When sending documents or file folders created on Apple devices to Windows, Linux, or Android, the recipient complains that the file/folder names are separated by phonemes.

This is the difference between NFD and NFC! My question is: is NFD for Mac bad? Is NFC good? Is NFD the old composite form, and NFC the modern, complete form of the 11,172-character Hangul?

Is the composite form bad? Or is the complete form better?

Because 99% of the posts on various online communities are negative.

I'm sorry to ask this, but as a South Korean user, the problem of Hangul encoding phoneme separation is unacceptably frustrating and infuriating.

Apple is known as a pioneer in personal computing, and they've made digital device accessibility a priority for people with and without disabilities. Why is this only true for Hangul?

Is there really such a difference between NFD and NFC in Chinese and Japanese?

English is alphabetic, so while there's no significant difference, there are times when certain characters are deleted.

[Re-Titled by Moderator]

Original Title: Unicode NFD, NFC Different