JK Rowling has given away about 160 million dollars.
That's a lot of good being done by one very good, talented and successful person. You might, then say that capitalism can be a redeeming force in the world. And while many do everything they can to change the world through the financial means they are blessed to achieve within a capitalist economy, this very meaningful good effort is inherently dependent upon the righteous conviction of the successful.
That means that capitalism must also be recognized as a "dependency system," in which the vulnerable need the powerful to give their wealth away. Yes, Capitalism can include powerful forces for good, but I'm not convinced it's an inherently good system. We should say about Capitalism what Winston Churchill once said about democracy: "It is the worst form of government, except all the others that have been tried."
A good system would eliminate vulnerability and destitution as a likely outcome, regardless of the goodwill of the few. Capitalism is not going away, and self-interest (the all-too-human basis for its global dominance, usually trumpeted as "individual rights") is here to stay.
I'm just saying that we shouldn't be so proud of free-will offerings.
A successful person of faith who lives in a capitalist society should use language like "obligation" and "responsibility" and "bearing the burden of the other" to describe their giving.