It is possible for the reader to quit the story if he starts receiving too much information; it becomes boring. The same is true with too little information, which in turn makes the story confusing. The secret to prose reduction is to know which things to take out without diminishing the essence of the story… and when to stop.

When we provide too much information, we make these mistakes:

Rambling

You start describing something apparently interesting, it might be an object, a landscape or a philosophy of life… and then you start to beat about the bush. You cannot stop. I bet you have read long discursive paragraphs in which the author tries to sound poetic or lyrical if not directly encyclopedic.

This is caused mainly by the lack of a responsible edition because these mistakes usually are taken care of during correction. A good beta reader would ask: were three pages really necessary to describe the strange and hypnotic shine of the light over the surface of the lake at sunrise?

Redundancy
In the real world it is necessary to repeat things. You tell your significant other about something that happened on your way to work, and then you tell your colleagues, your parents, your friends over dinner, at the bar, etc.

For the reader, finding the same information in several contexts is a repetition of the same thing once and again. Not to mention that you should never repeat yourself in the same page. Readers need to be reminded on occasion and maybe a plot is complex enough as to be explained but there are ways to make every version of the tale unique.

Depending on who is listening, the version of the story might be different in some details. When the information repeats itself the moving parts are the ones that call for attention.