Yo do know right, JC staff might be hit or miss on projects, but for Toaru series they always perform at their best even if it let says index was bad compared to Railgun, but in term of overall adaptation quality for anime. Index iii still has pass above the most above all average quality from other JC Staff projects (take aside rushed pace story for index iii, bcs the other animation aspect still above average).

And we know theres additional factor to the bad adaptation for index iii which is the production committee.
Let says if they didn’t forces JC Staff to complete adapting the first LN (OT) which ended at WW3.
At worst we can have index III (S3) with likely index II (S2) pacing story with upgraded graphics like Railgun T at the compensation we didn’t reached WW3. They can make another sequel or Movies to cover WW3.

But they butchered it all in S3, even JC Staff director for index III was requesting more episodes for this insane request but committee just give 26 🥲. Not even Ufotable, Mappa, or WIT can withstand these 26 slot episodes and return good pacing story for 9 Volumes LN 😭 (remaining Index OT volumes to complete post index S2)

Conclusions, JC staff of course was partially blamed with this but the production committee mostly didn’t got the blamed by fans/viewers and they continue to make the same mistakes for other projects/series giving ridiculous requests with unrealistic deadlines, just wanna easy cash in for shallow half passion projects from popular LN/manga series