With a rights of survivorship clause you can ensure that your partner will be able to stay in the purchased property or become the full owner if you are no longer there. This may be useful if you live together de facto or in a legal partnership, but also in other situations.
The majority of employees are covered by a group insurance plan, meaning that part of their salary is set aside for later. Once they retire, they receive this accumulated reserve. But what if you don't have a group insurance plan? Or if the savings in your group insurance plan aren't enough?