The right answer is Fluency. This is defined as the skill to express oneself simply and coherently. It fascinates the reader because something fluent is easy to get as much as it is attractive, so it doesn’t get the reader bored instead it makes them want more about it.
The writing trait that leaves readers wanting more is Fluency
Explanation:
The sentence fluency in writing has the rhythm and the flow of the language the author is using to convey their message. It involves how does it sound when read at loud how does it go through our ears and catch our senses by the cadence of its combinations of length in every line.