Man my brain has to be so weird. Cause I have literally the opposite feeling. Basically nothing has happened and we've mostly just been spinning our wheels waiting to grind sealing and FOOM XP
Honestly, I don't think the two are all that mutually exclusive. Putting out fires may be necessary and important but it doesn't really create the strong narrative throughlines that you get when we're proactively actualizing our goals.
This encounter with Hidan and associated Jashinist fallout? Interesting, dangerous, important, but 100 chapters from now I probably wouldn't be able to place when in the timeline it happened. There are a lot of things like that, story arcs that flesh out "Hazou's adventures in Marked for Death" without feeling like they're integrated into the main story and core plot beats.
(Which, again, not to say they don't have an impact. Our talk with Hidan may have distracted Sasori and bought us extra time for necromancy, for instance.)
In the respect that we
have been working on main plot stuff, we haven't seen a breakthrough yet. 3D Sealing is still languishing as a theoretical discipline, and necromancy progress is a bunch of seal research that hasn't paid out yet. Just as before, despite the plot points being important and necessary we aren't in a position to feel anything more than the investments we've spent. The tree is growing but there are not yet any fruits.
When we do strike gold, when the tree bears fruit and the main plot comes to a head as we make important decisions with the fate of the world in the balance, it'll all feel worth it because our eyes will be on the thing we achieved, with so much work put into it. But here and now we can only see the work put in, so the satisfaction of a goal well-achieved isn't real yet.
In another story, another world, we could have maybe skipped over all of this. A non-quest story could line up some dominoes and timeskip from the start of the necromancy grind to the day Hazou opens the rift. But part of MfD's quest nature is that, to earn our victories, we have to control Hazou every step of the way. Each seal in the Minato chain needs to be voted in, decisions to be made on the tradeoff between speed and safety, whether to multithread with SC and what else to research if so. This limbo period, where we put in work and it seems to lead nowhere yet, it's an unfortunate consequence of the fundamental nature of the game. But it won't last. It never does, we always find our way back to the main plot sooner or later, and then we'll save the world or doom it or whatever the cards have in store for us.
(Also, strictly personally, the EM cabal feels like a pretty "main plot" thing in my mind, so that big fancy Chapter 600 where it all comes to a head and the world is irrevocably changed as a result of it feels very much like meaningful motion to me. Regardless of whether it was a good decision or a bad one, a reading order list certainly wouldn't describe that chapter as skippable.)