The other answers do not address your very question about something you may have missed, making the end meaningful. Well, give me a try.
The following answer tries to make sense out of this film and contains massive spoilers. If you have not seen it yet, or are unable to admit that it possibly could be meaningful, stop reading!
Setting the stage
- Over the whole film, there are two contending pictures of Superman: The picture of a morally upright, god-like being transcending humanity (the picture present in most of the public until the events of Man of Steel) and the picture of a false god, a finite being that pretends to be better, but in fact is not (the picture drawn by Alexander Luthor and Batman).
- On the roof of the LexCorp tower, Alexander Luthor finally reveals what has been prefigured throughout the film: that the seed of the second picture has been seeded only by him, germinating in human's fear and especially Batman's and Wallace Keefe's hate and anger due to their losses.
- After the nuke exploded, it is shown that Superman is able to regenerate from advanced bodily decay. He is about to decompose before the sunrays hit him, as indicated by some particles parting from his face. He looks dead by then.
- Right before the last scene, it is said that his body is at the small funeral, by comment of Bruce Wayne regarding theatre at the east coast.
- The words written in the central funeral 'If you seek his monument - look around.' together with the words spoken by Batman to Wonder Woman indicate that Superman is seen as a saviour-like figure, wakening the good in all of us by the example of his self-sacrifice for the very people that questioned him.
- In the background, some heart-beating like sound
- CUT - prison scene with Luthor indicating the arrival of Darkseid once again - CUT
The very last scene
- Louis throws a handful of earth on the casket, metaphorically burying him and turns around
- In the background, there are once again heartbeat-like thumps. First a single one, then a complete double-thump.
- We see two grave diggers waiting for her departure
- Close-in on the earth on the casket, increasingly dramatic music
- finally the earth starts to rise from the casket - FINAL CUT - just verified by looking closely at the scene in slow motion once again.
The very last point would not make sense if Superman actually was done terminately. It would rather have shown the grave diggers burying him. Additionally, the whole plot works towards revealing that all the envenomed perceptions of Superman were plotted by Luthor, culminating the fulfilment of his destiny as a Jesus-like saviour (remember Dias Del Muertes scene?), including self-sacrifice that purifies humanity from all doubts, uniting them and - in the end - resurrection.
I do not claim that it is a good plot, but it actually is more than most people make of it.
As per comment of @ThaddeusHowze under his answer: It is entirely possible that it will turn out to be a theft of his body and we will see a resurrected, but twisted Superman in later films. But it does definitely not make sense to bury him at this moment, i.e. think that he will not play his role in the two Justice League films.
It turns out the reconstruction of the story was right on spot, as validated per the first Justice League film. Even the "oh my God, Supes turned bad" theme was included. Don't know if that's a good or bad thing for a sequel to be so predictable, I'm tending towards the latter.