How can we reduce suffering, inequality, injustice, and death? The old society had some good ideas. You would be permitted to have children if and only if you performed some legendary task of heroics or invented something society-changing or happened to be selected by random lottery. It was a privilege one earned voted on by those who proved their worth and intellect, not a right. If not, you were free to have a wonderful, dignified life, unless you broke the law, in which case you were banished to the wilderness, a de facto death sentence, but not always. It was going quite well actually. Until, through lack of foresight, enough of the banished managed to survive and became numerous enough to overthrow the ruling society. And here we are today. War, suffering, overpopulation, and all. Perhaps order will be restored someday. Until then, here are some, a bit more pragmatic, thoughts for your consideration:
Suffering, being a pronounced, elevated, and prolonged state of undesirable emotion or sensation? Many types of suffering are self-inflicted or otherwise easily-preventable. This would require removal of free will and personal autonomy in favor of government mandate over what a person can or cannot do and say. This would lead to more suffering, whether or not it ultimately reduces suffering writ-large. Other forms of preventable suffering, and biologically-related suffering (hunger, thirst, exposure to the elements, etc.) become equally as complex to solve. A scenario or thought experiment I like to go to that seems reliable is the "last man on Earth" scenario. What if, everybody, and everything other people invented, were to disappear, right now? No one to blame for anything, the world is literally yours and yours alone. Would you still not only eat by the sweat of your brow? Have dangers such as finding and maintaining shelter, avoiding predators, and sheltering from natural events or disasters, and even being entertained and not losing one's sanity? As you can see, it's not so simple. Sure as a result of the progress man and society has made, all efforts and struggles across the board should be lessened as in this case society is not the sum of its parts, but something far greater. Still, a world without suffering, is a world without personal choice and excitement, as if there is no risk for negative, there is no purpose or appreciation for the positive.
Inequality is another one. People will always be unequal in some way. There will always be someone stronger, someone smarter, someone happier than you, regardless of if we were all born with the same "starter class" as if beginning a new fantasy RPG. Because life is not an RPG, it's life. The cosmic role of the die decides whether or not we are born tall, short, strong, meek, or even disabled as well as into a rich or respected or large family or abandoned at a stranger's doorstep. That's why it's life. It goes back to the classic socio-economic questions: Should we cease rewarding people for being productive and ingenious and would this not weaken a society that does so where other societies that do not get ahead and advance in all ways, inevitably gaining the means and eventually rationale to overpower the former? Do we completely devalue the responsibilities of creating life to a "meh. I feel like having a kid today. Other people will take care of it so, I don't have anything else planned today, guess I'mma go do that now" attitude toward life itself leading to inevitable overpopulation? This would only increase suffering.
One man's punishment is another man's cruelty, and yet another man's mockery of justice. Goldilock's and the Three Bears, one bowl too hot, one bowl too cold, and but one just right. Some say punishment is too severe, some say it's not severe enough. If someone accidentally kills your child through no intent ie. drunk driving or firing a gun during New Years, you will likely opt for the severest punishment even if you discovered the perpetrator was suffering or perhaps experienced a similar loss whereas an outside observer especially one who never felt the same pain or is ineligible to (does not have a child) may wish to be more sympathetic as "it could happen to anyone and was a freak accident", etc. Even in a wholly fictional "perfect" utopian government and resulting system of justice with zero corruption, racial, social, or economic bias, something ran by an AI for example, it still can't be everywhere at once. Evidence can still be erroneous or erroneously produced (placing fingerprints or other evidence, or people flat-out lying in unison). So like most negatives in life they can only be greatly reduced, unlikely to be eliminated altogether. Such attempts to have done so only resulted in unfathomable amounts of suffering before ultimately leading nowhere.
Death is part of life. Health and safety is a factor. Again, requires government mandates and restriction. Should we imprison people found smoking or eating fast food more than 3 days a week in order to prolong their own life? Outlaw extreme sports or hobbies such as scuba diving, skiing, or mountain climbing? You see where it becomes difficult. Again, a world without suffering is a world without personal choice.