>>281156902
>Vol1 26570
>Vol2 72890
>Vol3 88427
>Vol4 135000
>Vol5 138989
>Vol6 146000
>Vol7 133502
>Vol8 122490
Plenty of things.
But looking at how series lost about 25k readers between vol6 and 8 SBA arc is certainly the problem.
Japanese readers formulated it quite well.
>Betrayal wasnt handled well
>Overall the ending was predictable as hell from the get go so there was no excitement and almost whole year of predictable tedious downer grind felt bad
>Side characters that people loved were benched (in case of newcomer Uruha - he was benched too)
>New side characters (Hiruhiko, Masumi, Iori) are either unlikeable or boring
>Focus shifted from Chihiro to Samura and Samura was annoying
>There is the discrepancy between how Takeru is praising Samura and how readers are seeing him as a piece of shit retard who created the mess for everyone; lack of punishment made the whole resolution deeply unsatisfying
>WPS spam is hella boring
>Reused panels became laughed at

This arc was an excersice in mediocrity across the board (art, action, character writing, plotting, storytelling, worldbuilding etc).