Vorathiel

I’ll agree with you and disagree with you. The first line is not 100% identical to the second. An ellipsis can be (ab)used to slightly alter the tone of a sentence, but only when it appears sparingly in a text. When every other sentence ends in an ellipsis, however, you lose that ability.
When you highlight 80% of the lines in a textbook, you’ve done the opposite of highlight. 
Building off Rooke’s point, that ellipsis then needs to be paired with tight writing to achieve a desired effect. Throwing an ellipsis at the end of a line is like putting glass to a furnace. You’ve loosened the voice and created something pliable, but unless you rework it with a craftsman’s eye, all you end up with is a directionless inflection — and a shapeless lump of glass. (Which I suppose would be useful for hucking at Rooke’s head, but not much else.)

While I agree about almost everything written in this post, I just feel like one, important thing was omitted.
It's all about proffesional editing of text. Also - in probably most of the cases it doesn't even matter if ellipsis is cut.
But.
There is something I used to call 'melody' of dialogues.

Just look here:
These are NOT the same sentences. Why?
It's simple. If sentence is written with a single dot at the end, it sounds in your head, while you're reading it, with fast paced, 'strict' voice. But if you add ellipsis, it's no longer the same. Fast paced voice is gone, and you have kind of melancholic and/or bored voice in your head. Melody of this sentence is going lower in tones and longer in sounds near the end of that sentence. It's important in dialogues to keep that, because otherwise (especially in vns, when we have no narrator telling us things like 'he sound bored when he said that') we would not know how this dialogue suposed to look.

To emphasize I'll write down some improvised dialogue.
It's not hard to believe that those characters have 'their shit together' and without delay they're starting to work.
But look at this:
But here it's impossible to think that of character A. He sounds lazy, sounds bored, sounds like he don't want to do it. ("sounds" of course, in your head, while reading)

I believe same thing was here:
Fred added that ellipsis just to exagerate that sentence, to make it sound differently, sound less bright, less strict, more lazy. Am I right?

So - it's important to keep ellipsis at the end oif sentences in dialogues, because they're dictates the rhytm and melody of voices.