I don't think we really appreciate how nearly perfect the world is. We lose sight of this because we have to concentrate on fixing the things that are wrong, or at least limiting or avoiding them.
What grounds are there for maintaining that the world is "nearly perfect"?
Consider the attempts to describe Heaven. They tend to be shallow and saccharine -- so much so that a fairly common theme in modern stories is an apparent Heaven that turns out to be a kind of Hell.
Related to the above are the many plausible-sounding stories about the terrible side effects of trying to make major changes. Examples include the stories of evil genies that grant wishes literally but with devastating effect, "The Monkey Paw", the story of King Midas, the real-life stories of many lottery winners whose lives are turned upside down by their very success, and the horrible results that historically attend Utopian regimes.
In contrast, we are pretty good at imagining Hells. Most such imagined Hells are, of course, about as shallow as the imaginary Heavens, since they are the products of people who have a poor understanding of human beings and concentrate entirely on physical pain, but there are others that incorporate psychological and even spiritual horrors.
If all our attempts to imagine a world significantly better fail, but our attempts to imagine a world that is much worse succeed, this is evidence that we live in an exceptionally good world. This in turn is evidence of God.
Notice that the few things that really would make the world a better place -- an end to violence, disease, and poverty -- are the kinds of things that would be straightforward to fix if we were all really willing to stop doing the things we shouldn't and start doing the things we should. This is evidence of the Fall -- of the fact that our own misbehavior is responsible for the most serious defects in the world we live in. (However, as noted above, Utopian schemes that try to eliminate the consequences of the Fall by pretending it never happened inevitably come to grief.)