the problem with philanthropy as I mentioned is that it only serves that public good favoured by the philanthropist, i.e. Bill and Mrs Gates' vaccine fund for Africa. It doesn't necessarily follow that the state will redistribute its resources to balance the inequitable distribution of funds by a philanthropist.
The power of taxation is to have money spent on those things that we as individuals might not choose to have it spent on.
I see philanthropy as a more a moral imperative or duty, but not necessarily a social good to do anything more than support the role of taxation. It can never be equitable, and it almost certainly will never be more than a few percent of redistributed wealth anyway.
Bring on more redistributive taxation on income, preserve an incentive to invest and save though, simplify the system but leave total tax take around 40% of GDP.
