Babies never understood

In Sodom and gammorah, in the flood and many other examples God actively kills children and even infants. Why? They never made a choice to do right or wrong let alone understand it. Nor would they of understood the sinful actions of thier parents. Why were they not just spared? Love is enacting justice on those even who never made a choice to go against him? Can we REALLY call that just? These are questions I've been brought with and honestly I can't find any good answer. If we all know they couldn't understand or choose, then by humans standard they don't have a right to die just because of the sins of the parents. That goes against practically all of what Jesus taught others do not get punished for someone else's sins. We aren't worthy of that i thought. Yet these babies faced the same annihilation. And from an outside perspective many find it the opposite of just but cruel and monstrous. People claim God lied about His nature and benevolence/ love. How do we explain this? Because from a human perspective somthing that isn't able to make a choice shouldn't pay for a sin it's never committed let alone understand what sin even is or what a thought is.