The "why" questions people ask about evolutionary biology are the carry over of theology into the understanding of evolution. People still need to believe there is a fundamental reason the world is the way it is. A similar theological carry over is the belief that we are better suited to the environment we evolved in. This is akin to "golden age" thinking, that the world today is somehow not right and if we return to the origin things will be better.

At a fundamental level causality doesn't even really make sense in evolutionary biology. You can ask the question "what benefits do this feature provide", but you can never really say that's why they evolved. In the end you have the traits you do because, at point in the species development, they didn't make you die faster and some helped you survive better, but it's not really possible to disentangle these.

Likewise people don't really understand that in evolutionary processes both the species and the environment are constantly changing. The notion that a species is "adapted for a particular environment" is somewhat nonsensical because "the environment" is never really fixed.