This sutta shows good news for humanity, and reason enough not to be too hard on us, we are doing pretty good stuff(see the article below), since our population is increasing(although its said with world estimates that we will top off at about 9 billion, and decline from there).
“Master Gotama, I have heard older brahmins who are aged, burdened with years, teachers of teachers, saying: ‘In the past this world was so thickly populated one would think there was no space between people. The villages, towns, and capital cities were so close that cocks could fly between them.’ Why is it, Master Gotama, that at present the number of people has declined, depopulation is seen, and villages, an.i.160 towns, cities, and districts have vanished?”
3(1) “At present, brahmin, people are excited by illicit lust, overcome by unrighteous greed, afflicted by wrong Dhamma. As a result, they take up weapons and slay one another. Hence many people die. This is a reason why at present the number of people has declined, depopulation is seen, and villages, towns, cities, and districts have vanished.
You can find how the world is improving in this article -https://www.vox.com/2014/11/24/7272929/charts-thankful and checking out people like Stephen Pinker(https://www.amazon.com/Better-Angels-Our-Nature-Violence/dp/0143122010).
Don’t allow yourself to be too mired in the negative aspects, watching the news you may think it’s all going to hell, but it’s not,at least not until our population begins to decline ;).
As Sam said to Frodo in the Lord of the Rings:
Frodo: What are we holding on to, Sam?
Sam : That there’s some good in this world, Mr. Frodo. And it’s worth fighting for.
Go out and do good deeds for the good of the many folk. Doing good deeds, acting skillfully and wisely in the world, and helping others is how we fight against our decline, not fighting , opposing, and arguing with others.