I want you to join me in a horrific thought experiment. Think of someone you love or at least really care about who is young, not into risky behavior and is relatively stable. Now think about the last time you saw this person. Now, imagine that is the last time you ever saw them or spoke to them. Imagine that they simply vanish. Go to their house and find it just the way they left it (maybe even with food on the table). Find their car, their wallet, their own family and friends...but you never find them.
Having a loved one vanish is, to me, the worst experience one can have. Not only is there no action you can take (besides maybe randomly looking for them), there is no new information to act on. If someone has been kidnapped, you get a demand. If someone has been hospitalized, you can find that out. If someone just vanishes, there is literally nothing to be done for it. You can't help but imagine horrible scenarios. Eventually, maybe you cling to one or two positive possible outcomes. But, in the end, the not-knowing is a torture no one should have to endure. Trust me on that one.