Why are we not all dead?

I’ve often wondered why Darwin’s theory is not tested by taking it to its logical conclusion. If Darwin’s Tree of Life branchings are all blindly striving for dominance, should not something like an omnivorous monster that consumes everything until its species expires eventually evolve? You cannot explain it by saying that such an eventuality would not serve it’s ultimate survival. Evolution presumably has no such goal. Some would say that we are that monster species but the evidence does not support that conclusion.