
Originally Posted by
Prothescar
Because that scene takes place five hundred years after the ending of the original game, plenty of time for nature to start reclaiming the land after an apocalyptic event wipes out a city, assuming we're talking about the full thing that we don't know whether or not the cast saw the ending to.
There is no evidence in hat scene that Midgar wasn't destroyed and that the world wasn't damaged by Meteor. Again, it's a desolate wasteland from the point of view of the vision. This hardly begets the notion that "everything is fine". Red XIII reacting to a, by your interpretation, overwhelmingly positive vision with a response like "a glimpse into the future if we fail here today" as if they wouldn't want it to come to pass, when at that point they've only been given that specific scene, makes no sense.
From their point of view they don't even know that Sephiroth summoned Meteor to begin with. From their point of view they've seen visions of a future where a meteor collides with Midgar and they want to stop it. The current theory that I subscribe to is that Sephiroth is feeding these visions to the cast in order to have them subvert fate, as now they believe fate has ordained for Midgar and perhaps the entire planet should be hit by this meteor, due to the visions that Sephiroth fed to them. They don't know that they succeeded. They don't know that they won. They've been manipulated into believing that they failed.
Sephiroth wants this because he does know that they won, and that if the time line continues on its due course he will fail again and be killed. He wants the time line changed so that he can rewrite it as he wishes and attempt to succeed instead.
The three colored phantoms representing Tifa, Barret, and Cloud trying to prevent this from happening, aka the original post you said makes no sense, makes sense in this context because they're trying to prevent a future where they don't win.