I understand perfectly what you're saying. And as I've stated before, most people are not evil, they want the best for everyone, but in the end, we're also very misguided, so we really don't know how to achieve that kind of utopic success.
The biggest obstacle we face our current "people stock". A lot of good people on the world, but even good people can do bad things because they don't know better.
And on top of that, we have a lot of important things that are being left aside and they're essential for a peaceful, decent world. We put a lot of faith in the material stuff. We think that if everyone has all the basics in life, they all should be happy. We are convinced that if people have food, shelter, a good non-toxic job, healthcare and a society free of things like oppression, racism and judgement, everything will be fine. But at the same time, you see people who have that and more and yet, they're still unhappy and capable of doing terrible things.