The text is pretty explicit. We disobeyed God, so God cursed the ground. (Read the next few verses). We have to toil, because we lost the cooperation of the natural world. And the fruits of our toil are in no way promised to be purely beneficial. We can use natural resources in such a way that can be dangerous for us because we have such freedom.There's nothing in Christian teaching that posits God to have such harmony was taken away. Genesis 3:17"
We may be the main beneficiaries of creation, be we are not the sole thing that exists within it. Not every plant is "for us" to consume.