I hope you would agree, it is wrong to see people as totally atomized, neatly seperated, each in their own little castle with their own small set of things. We are all part of a World just as that World is part of all of us. Sometimes we make it a little better and sometimes we make it a little worse, but surely it is not as simple as to say anyone is the sole cause of their suffering nor, that they are the only recipient. For example: would it not be terrible for those, that love them to lose such a very dear peace of their world, and as an extension of themselves, even if it is in part responsible for their own demise?
You also mentioned natural selection, but it is clear, that not all thing one could label natural are good, just or desirable. ‘Can we perhaps even build a new nature?’, ‘In a world where we can sustain everyone, should we not just do it without any kind of selection?’ - those are just two questions, that come to my mind, but I don’t feel like thinking about them, still wanted to write them down.