As others have said, what would you devote your life to?
First of all, I can think of a lot of philanthropic causes. We need more, better, cleaner, homeless shelters—and programs that help the homeless get housing and financial assistance and jobs, if they are capable of work. There are even sober people who are victims of abuse and may find themselves alone and terrified and left with nothing. Or, proplr who have lost their job and have little prospects.
Some communities need parks, community centers, health centers, and even schools.
Don’t discount our need for humane, no-kill animal shelters and animal sanctuaries. Animals suffer, too, at the abuse and neglect of humans.
And—just to be able to give people in need A LOT of help, whenever you find them. To go around, perhaps anonymously, helping people in need.
Of course, if all this still seems effortless because of your wealth, think of all the good you could do as a volunteer, a missionary, or even an artist or writer (if you could discipline yourself) if you did not have to work tiring hours just to pay bills and meet your own basic expenses.