Endgame has frequently been described as a ‘culmination’ because on top of everything, it is also the climax of the MCU’s entire existence, which has spanned a decade and 22 movies (including Captain Marvel and Endgame).
But acting as the second half of Avengers: Infinity War isn’t all Endgame has to do.
And we don’t know for sure, but Endgame may or may not also provide setup for the next stage of the MCU.
Bigger than that, it is also the concluding chapter in the Marvel Cinematic Universe’s Phase 3.