system
Given the following post, respond as if you're commenting on Reddit:
human
[D&D] Why does the skill, "use magic item" require the charisma stat modifier?
gpt
Charisma represents force of personality and innate aptitude for magic in D&D (and a few other seemingly unrelated things.  Its a bit of a grab bag stat).  It's the same reason why sorcerers and bards use their charisma bonus for spellcasting.