If you have more money than anyone else on earth, the highest leverage use of that money is going to be to fund projects that require more capital than anyone else can afford to fund and that governments are unwilling to fund. That way you know you are actually adding to the opportunity set and not just displacing someone else. The difficult part is, of course, deciding which of those projects that only you can fund will actually be a good bet, but that doesn't change the fundamental calculation. Not sure if that's Gates' strategy, but it would make sense if it was.
Actually the highest leverage would be to bribe electable politicians to get governments to be willing to fund your projects. It’s remarkably cheap apparently to do.
> but I expect the [Gates] foundation will spend more than $200 billion between now and 2045
Top 10 individuals in the world worth $1.77 trillion
The U.S. government has spent $ 3.57 trillion in fiscal year 2025
So Gates spends 10 billion/year which is an astonishing 0.2% of US government budget