Option A) The money is taxed and spent on HIV research.

Option B) He retires and (maybe) gives it to support HIV research.

So the question is, interest and efficiency.

It's possible in may situations for charitable giving to have greater efficiency, by leveraging the knowledge of the investor, directing the money towards really effective outcomes. Or not. Then there is the public interest.

Option C) Reduce the market power of monopolizing entities, in which case instead of gigantic profits accumulating in specific centres, you have workers, suppliers and consumers getting a better deal across the board i.e. Foxconn staff having more income, consumers getting better prices etc..

I like Option C.

I like Option B when there's effective leadership.

I like Option A when governments are really smart with their investment or redistribution.