We go to great lengths to ensure our children are cared for - we breastfeed, cosleep, protect them from slicing objects, babywear, babyproof, keep them rear-facing as long as possible, don't hurt them, keep them from those who would break their spirits, and so on. Of course we do. So, then, let me ask you: does this only extend as long as we live? Shouldn't we continue this in case of our accidental demise? My responsibilities to my son do not stop simply because my heart stops. I am his mother always, thus I will care for him always.
Without plans in place for our son, he would become a ward of the state until they find a guardian for him. Of course, they'll try to find a guardian who is also a close relative, but that doesn't mean that's what I want for him. I also don't want the state having a say in any of it even for a second. As if losing his parents wouldn't be traumatizing enough for him, he shouldn't also have to be in a state of limbo with strangers making decisions for him for even a second. Thus, we protected him from this potentially brutal fate. We chose a guardian, we chose a guardian in case that guardian is unable, we set up beneficiaries and contingencies - basically, we did as much as we possibly could to care for him in the case that we were no longer there to physically care for him ourselves.
This doesn't have to be an expensive, suit-and-tie in a lawyer's dark office type of venture. You can take care of these items quite inexpensively, swiftly, and easily with the help of online legal services. Shoot, you can even make that a Christmas, Valentine's, birthday, Groundhog's Day gift to yourself or your partner, so you don't feel like you're reaching out of your budget so much. Then keep them in a fireproof safe or even in a plastic baggie in the freezer - somewhere safe. Distribute copies to those affected. Update as needed.