Philanthrophists find it rewarding to help those in need. The motivation of wealthy people to serve the society is because lies in their emapthetic personality, the benefits of this trait is that it increases the respect of those wealthy people in the society.
Foremost, because happyness is relative some people do not find any pleasure in their own wealth, instead they find happyness in helping others. To elaborate, some individuals have a empathetic personality, and this personailty is usally the result of childhood environment. This is because, if a wealthy child found happyness in helping others, he would try to continue this practice with other people. This practice will nourish his empathetic personailty, and when he grows up he is likely to perform this work on a larger scale like helping other countries or communities. For example, a wealthy muslim of Saudi arabia donated one billion dollars from his own networth since he grew up in a muslim family, so the environment influenced him to help other people.
Additionally, this behaviour will benefit the individual himself because he will be more liked in the society for his work. In other words, humans like individuals who help others. For instance, a famous burger franchise in our country decided that it will donate 10 dollars to the communities for each five burgers it will sold. Hence, Not only this attitude increased their sales significantly, but also the founder of the franchise was valued and respected by the community.
To conclude, happyness is relative some people find being wealthy rewarding while others think in a opposite manner. This unique attitude attracts society towards these humans