[ Well, that's something at least. Sephiroth not being quite as delusional as Cloud had thought... ]

That's not true. The planet is healing right now.

[ Without Shinra siphoning Gaia's life force, there's been signs of healing all over. Greenery in places there had previously been none, cleaner air and water... ]

It's going to take a long time for it to fully recover, but it's the better option over killing everyone on the planet.