I think more likely is that bill and Jeff built their wealth through their businesses, which they are still directly involved in. Giving away their wealth would be equivalent to giving away the business they built from the ground up
I think there's also a question of efficacy. Bill and Jeff are really good at turning $1 into $10. Melinda and Mackenzie? Not so much. If bill or Jeff wanted to maximize the amount they can give, the best strategy would be for them to continually earn until they die, and then donate it.
I agree that Bill and Jeff are better at exploitation at scale. That’s how you become that wealthy. We are lucky they’re divorced and the wealth is in the hands of better stewards to distribute it to do good.
That's what it's about though. The amount THEY can give, not the benefit to humanity.
It's not like Bill and Jeff actually built any of these products themselves. Microsoft bought DOS. Right place, right time for that Nepo baby. Bezos at least had a normal family.