I enjoyed this work, it is thought provoking. Having said that, I disagree with the conclusion.
The world is complicated, difficult, at times incomprehensible, and yes even cruel. But then again, what is the world? Nature? Humanity?
Nature is ambivalent, not cruel.
Humanity is of course terrible at times, but wonderfully loving in other moments.
Is it cruel that a mother steals from another who needs it, in order to feed her starving child? Its complicated, its "incomprehensible" perhaps, but its not "cruel" necessarily. Its nuanced, its beautiful and terrible, but its not even an "it", its actually "us". We are the thing that makes this place so miserable at times. But we are also the thing that makes this world worth living in.
The "world" you describe actually not a place, but a people. Humanity is the "world" that you are describing, and yes we are cruel at times, but because we are free to be cruel, we are free to be truly loving. And therefore, when we are truly loving (self-sacrificial, generous, & scrupulous) that light shines all the brighter, amidst the darkness of today.
And lastly, I dont think its luck. Its design. The incomprehensibility you describe is a feature not a bug. Our creator gave us freedom, which gives us the option of cruelty, but as Ive said, that opens the door for real meaningful, genuine love, kindness, and generosity.
You cannot have one without the other. Freedom to choose includes freedom to be terrible to one another.