Spiritual Evolution and Planetary Crisis

According to my understanding, after the ‘physical being’ transcends to the ‘non-physical’ (death as we know it), the soul can reincarnate, if it so desires. If the purpose of the soul is to reach higher states of enlightenment at each rebirth, would this not imply that the children of each progressive generation will be more ‘enlightened’ than the former generation and should this not ultimately lead to the extinction of selfishness and hate?
While this concept seems idealistic, it also seems very simplistic – or does it really? Why then would there be so much poverty and misery all over the world? And why does humanity seem to be degenerating? I’m trying to make sense of all this confusion.
How are we going to fix this?