Why not use pay-on-death or transfer-on-death arrangements for personal property or beneficiary deeds for real estate?

These arrangements do avoid probate. However, they do not address the problem of management of your property during periods of incapacity prior to your death. Furthermore, these methods do not offer a convenient method of prescribing alternate beneficiaries or distribution methods in the event of a change in circumstances. For example, a P.O.D. bank account naming an adult child as a beneficiary would not provide a trust for the grandchildren if the adult child predeceased you or was killed in a common accident.