True, even when you are writing a scientific publication with a hard page limits (~8 pages), it is advisable to reiterate the core messages multiple times as you add more context and details:
= abstract
1) in this paper we show that X holds by evaluating Y against Z
= intro
2) the problem of A is important because B, however the X aspect was overlooked; we show that evaluating Y highlights real world challenges, in contrast to Z, that...
3) to sum up, we found that Y is better at Z because X
= related work
Z approached the problem as..., which improved..., but as we show further, this is not sufficient to achieve...
.. and so on - you circle around the main message over and over again in each section.
= abstract 1) in this paper we show that X holds by evaluating Y against Z = intro 2) the problem of A is important because B, however the X aspect was overlooked; we show that evaluating Y highlights real world challenges, in contrast to Z, that... 3) to sum up, we found that Y is better at Z because X = related work Z approached the problem as..., which improved..., but as we show further, this is not sufficient to achieve...
.. and so on - you circle around the main message over and over again in each section.