A big part of the pain and death in nature is caused by predation, animals attacking and killing each other for food.
It is better, I argue, for all living beings to live out their lives free from violence, whether by humans or non-humans. Violence is unacceptable as a part of nature.
Intervening in the natural order will require changing the natures of the various sorts of animals, or species. Left to itself, nature would continue to be violent as it has been for millions of years.
Humanity is beginning to awaken to the reality that all sentient beings are essentially like us, perceiving, thinking, feeling, being aware of the world, valuing their lives. And we happen to also live at a time when technology is advancing at incredible rates. This means that in the not too distant future intervening to veganize nature will not only be physically possible but also strongly motivated by core moral principles that are wisely accepted.