You did not say what I said. This is what you said:
I said it was patronising because you pulled this "you don't understand development" bit out of nowhere, I understand it perfectly fine - and you failed to explain why they found it possible when you apparently spotted it instantly, you're just waffling around the point. Devs shutting down, open world fatigue, Versus fans being picked on - none of this has anything to do with your or my point.
I'm saying when I saw that map picture for the first time long before now that I didn't trust it to begin with. You're looking back on it with hindsight. Your second post implies that you believed the model map was possible, you believed the FF15 devs, and you got suckered.
I'll explain exactly why I thought it feasible.
First of all, no one ever mentioned the scale. I saw estimates that it was around Just Cause 2 size, but I don't think there's been a pre-release size estimate for a videogame that's gotten it right - Fallout, GTA, they usually think they're far more massive than they end up.
Anyway, Just Cause 2 is demonstrably a videogame that exists and was put out by Square Enix, the FFXV dev team mentioned they were getting help from the same Just Cause devs on the engine. And most of the FFXV map is water or impassable mountains, making the actual area far smaller still - it's not impossible to imagine a game that trades out JC2's dozens of identikit bases and settlement for a dozen more unique ones and a higher quality campaign, especially considering the gulf in sales expectations and prestige between the Just Cause series and the Final Fantasy one. We also know that SE Japan are capable of much more because of their statements about how the bulk of work for FFXIII never made it into the final game.
They'd already shown they'd de-scoped the project from Versus by dropping the large city environments and heavily scripted action setpieces of the Insomnia intro, which seemed to eat up most of that projects development. The biggest urban environment left looked to be Altissia, which looked Beauclair from Witcher 3 size or smaller, and CDProjektRed managed to develop that and 30 hours of content in only a year.
Episode Duscae looked like it provided a great and feasible example of this, a square mile of explorable terrain with maybe one unique structure that you couldn't enter and some simple fetch-based side quests. Really you just seem to be arguing you can't hold them to the standards of other developers because they're Japanese and therefore incompetent, I don't buy that.