downvotes? I'm not sure how this rates those. Accuracy isn't really helpful to a five year old who doesn't yet have all the concepts needed. The tooth fairy isn't accurate either. Accuracy will get you an endless cycle of "but why dad?"
So keep answering until you can't, and then say "I don't know". Curiosity is something to be fostered, not shutdown with lies.
When they're a little older and have more capacity to understand a fuller, more accurate, discussion is possible.
Only thing I can come up with is to wish everybody health and a long life.
The aspect of it that people are objecting to is that it does try to explain why. It says "Your father needs to go back in the box so we can make other people", which simply isn't true.
That said, I'm not a parent, and I realise it's easier to be idealistic in theory.
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.
It's either that, or your child's future partner will have to deal with them losing faith in their parents, after so many things they were told turned out to be bullshit said to shut them up.