Does the very nature of atonement suggest that God, not humanity, was a failure?

I'm just gonna say here that God didn't make any mistakes. When He put that tree in the garden and told Adam and Eve not to eat from it, He knew what He was doing, and He knew what was gonna happen. He had it planned out then how He was gonna show us His Love Mercy and Grace on the cross, because without sin He couldn't show us that at all. And also still to come, because of what happened then He is still gonna show us how good and Just He is on judgment day. So in the end God's plan is not a failure at all. And those of us who receive His mercy and grace (by repenting of our sins and putting our faith alone in Christ for salvation) will indeed go to Heaven, and those who don't will feel His wrath, simple as that.