But there _is_ some good to balance death out, it's called life. And the lego analogy captures this idea perfectly and quite appropriately for a 5-year-old.
The lego analogy expresses the fact that we are not different from these other beings, and that we too must die so that life can continue. The death of an individual in this chain is always painful, but as part of the whole, it is just as it should be.