Allegiant - alternate ending

The Allegiant ending was not so bad but it made me empty. There were two reasons why I did not like it. Firstly the sacrifice as it is now seems useless to me. For Caleb it was more another grief than help (not thinking about Four...). And the second is the fact that they still didn't solve anything. There was no use of her divergence, if this did not help the word to become better, to find a solution for all these people from the fringe ... I really don't think that her mother would be happy is the story would ended like this.
All characters all belong to Veronica Roth, but I changed/added some parts! At the beginning I did only minor changes in existing chapters, but then everything is new. THIS STORY CONTAINS ALLEGIANT SPOILERS! Thank you so much for the reads, votes, and comments!!!
I am sorry for grammatical and other mistakes in the text - I am not a native (English) speaker.