It moves the plot, and it hasn't ended yet. It the next chapter is indeed the last of Elbaph, then it does seem lackluster.... But then there's Zou, which I loved, and it had no tension whatsoever. The lore drop alone makes Elbaph stand out.
We have no idea where Imu is going, but his move will definitely have consequences to the story. He also might be able to teleport somehow.
In any case, fellas, feel free to hate this arc if you dislike it so much, we can agree to disagree. I personally enjoyed most part of it including the flashback. I am still annoyed at DR bullshit and Shakky's plot, but overall Elbaph is a decent arc, especially compared to Wano and WCI.