I think that the issue is that everyone here is saying "everyone should do X", and that just doesn't make sense. Maybe everyone should just pick one thing on the chart and do that to improve the world as a whole? "People will have kids anyway, so that's not a good measure" could easily be reframed as "People will have meat anyway, so that's not a good measure".
We all have a sacrifice we're willing to make to be better, and we don't mind doing. Some people don't want to have kids, so they contribute that way. Some people don't want to eat meat anyway, so they contribute that way. If you want to do better, pick one thing and start doing it, even if it's not perfect.