Nature balances itself; it reverts back to maintain the balance; otherwise, the universe will dissolve before it is supposed to. It wont last the full cycle. Things are meant to be the way they are. The gravitational pull of moon and earth and all the planets, if it increases slightly or reduces slightly, what will happen?
Same way, What if everything becomes perfect? A world without any problems? No disease, illness, or worries! Wouldnt that be great?
So here is a story from Yoga Vasistha. Once Prahalada (crown prince of demons) attained enlightenment, a state of supreme bliss, he became undisturbed by the movement of thoughts. He sat where he was, like a statue.
For a very long time. The demons tried their best to disturb him: they could not. A thousand years went by. The demons concluded that he was dead.
Anarchy prevailed in the netherworld. Hiranyakasipu was dead, and his son remained dead to the world. No one else ascended the throne. The demons roamed the country freely, guided solely by their whims and fancies. There was utter disorder! In the meantime, the protector of the universe lord, Vishnu, contemplated the state of the universe.
(As Yogananda mentions in God Talks with Arjuna - "Cosmic Nature, Mother of all vibrations, has three phases: the creative, preservative, and dissolving states, governed respectively by Brahma, Vishnu and Shiva."
So the preservation of universe is department of Vishnu.)
In his own mind, Vishnu saw the heaven and the earth and satisfied himself that everything was in order in those regions (perfect world!). Then, he saw the state of the netherworld. He perceived that Prahalada was deeply immersed in the transcendental state of consciousness. Freed from harassment by the demons, the gods in heaven enjoyed a run-away prosperity. Seeing this, lord Vishnu thought:
"Since Prahalada is immersed in the transcendental state of consciousness, the leaderless demons have lost their power. In the absence of a threat from the demons, the gods in heaven have nothing to fear and hence nothing to hate. If they have nothing to fear or hate, they will soon rise to the transcendental state of consciousness, beyond the pairs of opposites, and attain liberation! This universe, which ought to exist till the natural cosmic dissolution, will thus abruptly cease to be. I do not see any good in this: hence, I think that the demons should continue to live as demons. If the demons function as the enemies of the gods, religious and righteous actions shall prevail in this creation: and thus will this creation continue to exist and flourish, not otherwise.”
“Hence, I shall presently go to the netherworld and re-establish it as it should be. If Prahalada shows no interest in ruling that realm, I shall appoint someone else in his place. Surely, this is the last incarnation of Prahalada, and he shall live in this embodiment till the end of this world-cycle. Such is the world-order. Hence, I shall go to the netherworld and roar to awaken Prahalada . I shall persuade him to rule the realm whilst enjoying the consciousness of liberation. Thus shall I be able to sustain this creation till its natural dissolution.”
The world has always been a place of balance, cyclical. So if you believe this, The overall pattern might be different in a different age (life might be better or worse than other ages). Still, everything is cyclical, it can not go out of whack towards too good or too bad, it will come back to balance itself. :) If there is a supreme power beyond what we know, most likely, it works like this.