I think the point of contention around whether it had the feeling/aesthetic of Final Fantasy comes from the fact it lent too hard into the Sci-Fi elements without having the more over the top/intentionally camp/fantastical elements to balance it.

FFVIII is probably the entry that has the most futuristic bent (you even go to space in a rocket ship), but even that has the imagery and theming of teenagers casting fire balls and the repeated ideas of knights and witches in the themes. Even the entries that bend more towards modern appearances (FFXV mostly) still has the characters being pretty anime boys with giant swords

With this lens, it could be argued the kind of 'cringe anime' stuff that some people argue against is actually baked into the DNA of the franchise, and it's removal creates a feeling of dissatisfaction. While the broad strokes of the movie align with some themes, in the end it just lacked the aspect that make FF stuff compatible with each other