And, without being gross - that is a very good reason to wear one. If a surviving family member has to wait six years for benefits because they could not find the corpse . . .
I have to agree with Rik. It is one reason. Saving a life is the most important reason. I know Rik agrees with that. No one is required to wear one if they don't feel like the loss of their life is a likelihood. Of if they simply feel like it won't make any difference. Or if they just don't want to be encumbered by a device that, in an unforeseen event, would contribute to their safety. Or.... There is no end to the reasons for not wearing one. I certainly have gone out on the water without wearing one countless times n the past.
On the other hand. If you are a world class athlete in certain sanctioned competitions the rules require it be worn. Why? To minimize the likelhood of your becoming a complicating statistic? No, to exercise maximum insurance against drowning where it can be mandated.
With the development of seat belts we got used to their presence. I put mine on automatically now because I don't feel as secure driving without it. Their effectiveness is clearly established. My teeth went through my lips as kid, in the 50s, when a sudden stop slammed my face into an un padded dashboard.
The availability of fairly comfortable automatic pfds can minimize the likelihood that your loved ones will live the rest of their lives mourning your accidental drowning. If it isn't because you feel at risk that you automatically put one on, whenever on the water, do it for them. Develop the "seat belt" habit to protect the ones you love. To make an excuse for not wearing one...Oops, did I say "excuse"? I meant "reason" is simply, selfish. It won't be your problem if something you didn't anticipate takes your life. It will be, one of the worst imaginable problems, for those you leave behind.
Wear your pfd.!! Even if it only means your kids or your widow will collect the insurance they need, in a timely way, to survive without you. Why not?