A lot of people seem to think that because they see a substantial amount of bad news, the present is worse than the past. (Of course there have been people saying that in every generation.) And “I’m losing my faith in humanity” is a common sentiment. (Really common: “I don’t want to live on this planet anymore” and other such memes are basically variations.)
And then there are people who just claim that people are basically bad and always have been. Some religions endorse this view.
These are two different ideas, but they’re not completely separate. If the world is in fact getting better rather than worse, that is also evidence that people have more goodness than the cynics give them credit for.
And it rather clearly is getting better. People who claim otherwise tend to be those who benefited from the injustices that were worse in the past than they are now, because equality is one of the most prominent areas of social progress.
But certainly not the only one. This is actually the most peaceful century in history, despite the news reminding us that we still have a long way to go in that regard.
And really, the bad news itself is evidence that things are improving, because a lot of it is things that,in the past, wouldn’t have been regarded as so bad or so newsworthy. The same things happened in past, but then, people didn’t care. Not as much as they do now, anyway. The thought that whether or not there was a war or a dictator on the other side of the planet had anything to do with how happy they should be about the state of the world wouldn’t have even occurred to people whose culture was less global. And how many white Americans would have been outraged over a black man being murdered by a cop in the 1950’s? Sure, the number that don’t care is still far too high, but it’s far lower than it was during the era that conservatives seem so nostalgic for.
The world is improving. Perfection is impossible, but it’s still the goal we should be striving toward anyway. It’s a good goal because it’s unreachable; if we set a lower goal we’d reach it and then stop improving ourselves any further. Anything less than perfection, anything that we’ll ever actually achieve, is a milestone, not an end point.
Now, as for the broader question of human nature, I think there’s some truth to the line from Men In Black (paraphrased); “a person is smart; people are stupid”. Bad ideas last longer than they should because people are less likely to question things that more people seem to currently agree with, or because someone in a position of authority promotes the idea.
People are good, but there are so many ways in which culture encourages them to be less so. From treating things that should be shocking as normal (or vice versa), to flat out telling people that obeying authority is a higher virtue than following their own conscience, the ways that people organize themselves make good people do bad things. Several philosophers have said that religion is the only thing that can make a good person do evil, but I don’t agree with that; nationalism, “honor”, prejudice, and various miscellaneous aspects of culture can all have the same effect.