When to Duplicate a Key and When to Replace It Entirely
https://direct-wiki.win/index.php/When_to_Duplicate_a_Key_and_When_to_Replace_It_Entirely
If your key is just worn but still works smoothly, duplicating it is fine, but if it's bent, chipped, or getting stuck in the lock, a new cut from a fresh blank is safer since copies amplify existing flaws.