Sweet and neat dots show a degree of calmness. It takes patience and care to do it consistently.
Slashed, dagger-like strokes meant as i dots suggest a tendency toward irritability and/or impatience.
Semi-circle i dots show a lighthearted, even a sense of humor in the personality.
Circle i dots are affectations executed by a writer who feels unique in some way but may not overtly show it. They are most often found in the writing samples of teens. However, many adults make them too. They see themselves as a little "different."
Keep checking the writings you come across. If you know the person see if any of this fits.
Omitting dots can mean an artistic choice to leave them off. That alone makes a statement. Look for artistic and consistent handwriting that is legible.Or maybe the writer thinks they are a waste of time and effort. An independent sort of person?
If missing dots are just due to carelessness, then "what you see is what you get." Beware if you are a perfectionist who likes to deal with precise people.