Given two parents, there are four grandparents. Sharing the load across six people is much better than sharing between two.
not really, overall the life expectancy is growing well over 80 years old. unless you live, like, in the woods and feed off berries and hunting or something like that.
and yeah sure there might be somebody that loses their parents at 15, absolutely. i'm sorry for them, but they are not statistically representative in any way.