Exactly, how did an inefficient development process give us VII\VIII\IX\X\XI in.. 1997-2002?Nope, it was just the tip of the iceberg.
Squaresoft's impressive output during the 90s was mainly (and sadly) the result of inefficient development processes. Sooner or later Squaresoft had to cut here and there because there were too many teams working on too many projects and too many overlaps over too many ventures. Of course, most of the games that were released were pretty great, even C-tier stuffs like Threads of Fate. But that approach wasn't going to be sustainable for a long time, especially with increasing development costs.
Sure, a lot of the 'fat' was never going to survive even going into PS2 gen, but i'll eat my hat if the mainline FFs of that age didn't pay for themselves twice over.