If you had a billion dollars, what would you do to make people's lives better? For most of us, this is like talking about what to do if you won the lottery: the stuff of daydreams, not reality. But if you really sit down and think about this problem, it's not an easy one to get a grasp on.
You could do immediate things, like feed them, vaccinate them, or teach them English. These are things where you pay ten bucks, you get ten meals. Easy to measure.
You could do systemic things, where you create a system that's then supposed to do things. Build a school, create a farm, build an irrigation system.
You could invest in systems, choosing winners over losers. Finance that business, support that government program.
There are other options, and it'd probably be interesting to go through them all one day. But at the end of it, you're left with the uncomfortable fact that thousands of other entities have invested trillions of dollars in making people's lives better and have very little to show for it. Entities much smarter than you, operating on a much greater scale than you can. Even if you're Bill Gates.
I'm not ready to give up and say the problem is intractable, but it makes me angry that so many snake oil peddlers, many of whom are politicians, sell the idea that these are solved problems; we just need the money. They are not.
So I wish Gates the best of luck. I'd probably bet on connectivity ahead of saving lives, because I think long-term it's more important for humanity to solve its own problems than to keep individuals alive, but heck if I'm happy with that opinion. And if I were Gates, I might just take us to task for that, as he's doing. Good for him.