The emotional payoffs are a feeling of control, love for their family and if they give to a worthy cause, the feeling that their life has had significance and meaning. Increase their net worth. A pretty safe assumption is that money is very important to anyone who has it - and they want your help getting more. The benefit is they are winning the money game and the emotional payoff is feeling that they are increasing their financial security and that they made the right decision working with you. Plan for a secure retirement.
Most advisors think their clients are afraid of running out of money when they retire.
This is only partially true. In America, if you run out of money, you won't starve. You'll simply lose your financial independence. A huge fear of wealthy Americans is becoming dependent either on their children or on the state. The benefit is a financally secure retirement.