They ruined a good thing when they stopped telling the story in chronological order.
The whole thing of narrating the story out of sequence and needlessly jumping back and forth between different points in time seemingly at random just made it a pain to follow and threw any previous attempt at coherent storytelling out the window. Suddenly jumping from the middle of one scene, to something completely unrelated that happens presumably years later in the story entirely without warning and without any continuity whatsoever is just messed up. It feels like you suddenly find yourself reading different manhwa that got accidentally uploaded on the wrong page.
In addition, the pacing is just awful. In the 'climb the tower' story, they will steadily progress through several floors, then spend several chapters on a single floor (endless eight, anyone?), then completely skip several floors, then asspull plot-armor from the floors they didn't cover.
Logically, if they're willing to spend so many chapters in one place, why can't they even spare one for all the others!?
I wouldn't mind following a slow and steady story about grinding. That's what this was at the start, and it was actually well done. But following a story that has no idea what it wants to do with the pacing and also chronologically jumps around all the time is just painful.
It was fun at first, but betrayed our trust shortly after. If you haven't started reading this yet: don't. It's not worth your time.