Free will. We - as a humanity - have chosen total freedom (or actually the illusion of freedom because being a slave to your physical desires is not a freedom at all) over living as God has created us at the beginning, and now we have to live with the consequences of that. Wars, diseases, starvation, inceldom, discrimination etc are a results of our corrupted nature. Saying that "God shouldn't allow this to happen" doesn't make sense because this is exactly what we have chosen. You can't eat a cake and have a cake, and you can't have a free will and live in a total paradise on Earth, without any option to rebel to God's Law (because no choice = no free will de facto)