All the great art should teach us that we can't take riches to the grave, it's too bad that this is being forgotten.
Then again, may be they already figured out how to make their lives meaningfully longer. I often think what drives 80 year old Bidens and Trumps to live the stressful POTUS life.
And I can think of only one incentive. Weird thoughts, but otherwise the dots just don't connect.
Different people are driven by different things. Some people genuinely want to serve their nation and being a president is a huge honor to the family. You become part of history.
Others may be serving their own interests as it gives them access to all information.
Others may just want the power.