My understanding from discussions with liberals on this:
They paid their taxes, so they don’t need to give to charity.
They are green/eco-friendly, that helps the planet, so charity is redundant.
They got the government to increase social spending. That policy change affects thousands or millions, and is more than what one person could give. So getting the government to lock up millions of acres or fund arcane research with others money is a “multiplier effect of good” and better than raising money to research or solve problems, like the March of Dimes or St. Jude’s hospital.
Another tip off is, Libs dislike leaving a tip for the waiter.
I just tell them that doesn’t satisfy, in the least, the REQUIREMENT that they, as individuals, be charitable, and viscerally they know it.
Any righteousness they feel is false, temporal and short-lived.