None of the three reasons you said is correct. Yes, a Simplified Chinese character contains less strokes than a Traditional one, but they convey almost the exact same quantity of information. You will understand this when you notice that although people in (Mainland) China and Taiwan wrote differently, they speak almost the same, using the same number of characters to express the same meaning.

On the other hand, there is a difference between Classical (Literary) Chinese and modern plain speech Chinese. The Classical Chinese, used in ancient times mainly for writing purposes, with its different grammar and vocabulary, does use less characters.