"cruel" is a human concept. Nature doesn't give a solitary fig for what humans think. Even if we perceive certain aspects of our universe to be "cruel" and merciless, it is just how the universe functions. It's often arbitrary, and seemingly without good cause, but that is because there is no underlying purpose, controlling influence, or wilful intent behind most of the things that happen in our universe, a great deal of it is just random happenstance.
"shit happens", as they say.
I doubt anyone would argue that the extinction event that wiped out most of the large dinosaurs was "cruel", yet humans are just another random species that inhabits the same planet, we have no greater right to existence, and if some misfortune befalls one of our species we perceive it as cruel because we have a shared experience with that other human being, but also because we're a pompous enough species to believe that we are, in some way, superior and subject to special favour by nature, when we aren't at all. We're successful, undoubtedly, because we happen to be the lucky species that hit the evolutionary jackpot, but the universe couldn't care less about humanity, and doesn't subject us to a special ruleset just because we have a degree of sentience, hence why it sometimes has absolutely no compunction in crushing us like the insignificance we are.
It's us humans who give humans special status in the universe, not nature itself, so I don't really understand anthropomorphisising nature and attributing human characteristics to it, as if it has some sort of conscious will, or a table of priorities and desires.
From a purely human perspective, yes, sometimes things happen to humans through no fault of their own that we would certainly regard as unfortunate, or even cruel, but nothing about that necessitates that nature gives us a second shot just because we were unlucky the first time around. That's just the human pomposity and ridiculous self-importance rearing it's head again. The universe doesn't make exceptions just because humans think it would be nice if we were treated differently or subject to special, magic rules.