I don't think the writers will spend lots of time showing us that there are lots of different time lines and showing us exactly what was changed and why, although maybe we'll see just a few. The main story of Lost IMO is that the two sides are fighting for control over the timeline to affect the ultimate result, i.e. the events which lead up to the scene on the beach, Ben killing Jacob. (However IMO there may actually be another ultimate outcome to the experiment that we have yet to see.)Therefore, the timeline we have seen, series 1-5, is essential to the plot. We have seen one possibility out of many which leads to the scene on the beach and that those events can be changed seemly in a instant when really it was a whole time line of changes. Lost is exploring some theoretical quantum physics in sci fi. We can see how these events on the beach can be manipulated by having a multitude of possibilities which are o! nly determined at the end by the opening of the box like in the Schrodinger's cat experiment.
Ultimately I think the point is that no matter what they do, they cannot change the fact that Ben killed Jacob. Having said that - it might not be that event that the two sides are trying to change.
Ultimately I think the point is that no matter what they do, they cannot change the fact that Ben killed Jacob. Having said that - it might not be that event that the two sides are trying to change.