But also, by your logic, I could bring more students into a school and only slightly ratchet up the molestation going on, and that would be a sign of success on my efforts to lower molestation in my school.
Yes, of course you could. The amount of molestation happening would go up slightly, but the amount of molestations endured per student would decrease, therefor, the problem would be less prevalent, the state of the school when it comes to molestations would improve.
There are many problems with this, and most of them boil down to the fact that it's not a closed system, but a system where you bring in people to fix the statistics for you, people that you put in an environment that is probably more negative than the place they were before, and by extension, you're also increasing the rate of molestation in other places by taking away people with low molestation rates, but... if all you're concerned about is the overall state of the school, then yes, that would be a solution. A terribly bad solution that you'd probably get fired for - and rightfully so - but a solution.
I'm helping world hunger by having more middle-class kids? It brings down the percentage of hungry kids, overall. Should I have more kids? That would help even more!
...yes, that also works perfectly fine, at least on a small scale. Because indeed, you've created a new human being who will likely never suffer hunger unless maybe if they're trying to lose weight, and as a result of that, some kid in Africa will probably have to give up half of a meal once a week as a result of the extra food that we now need in the western world. So yeah, f you make a baby, then you've essentially improved the state of world hunger - congratulations!
And I'm not trying to be offensive for no reason, I really mean that. If we're talking about the overall state of the world, and whether it's increasing or declining, then we have to look at the balance of people who have it better than before vs. people who have it worse than before. That's all that matters, and that may seem cruel, but it's not really - it's just the scope of what we're talking about. It is again perfectly fine to acknowledge that the world is becoming a better place overall, while also acknowledging that the number of people who are suffering in really bad situations is still on the rise.
Your correct statement that the overall suffering is also going up does not change the trend of the world, suffering increases not because the world is getting worse, but because people are getting more numerous quicker than the world is becoming better. You're just not arguing that the world is becoming "worse", you're arguing that despite the fact that the world becomes better when it comes to world hunger, the amount of people that suffers from world hunger has increased. And that's true - but it's not a rebuttal to the idea that the prevalence of world hunger decreases.
The part about "bringing in more privileged people" is not correct though, not in this example at least. Because while it's still correct that statistics about percentages don't capture the scope of the suffering in a world that is expanding, it's not really an issue when it comes to world hunger. Because...
And finally, are you saying that it wouldn't be objectively superior if the number of people went down? No, you're certainly not. You're using a metric. I am contesting the statistic you're choosing to use. Obviously, I prefer if the percentage go down rather than not. But you're driving down your percentage by increasing the number of people. Bringing in more kids into the school.
...I'm not bringing more kids to the school.
The large part of the population boom of recent decades has not happened in Western countries, so clearly, it is simply not the case that we've created more "privileged kids" to make statistics look more rosy. Population has increased mostly in Africa, Latin America, and South East Asia, those are, in large parts, also the areas that are struck by poverty and hunger. Because of that, the obvious assumption is that the percentage of people who suffer from hunger has gone down in areas that were previously struck by hunger.
And indeed, a quick and dirty google search confirms that decreased hunger in Asia is the main source that fed into the reduced prevalence of world hunger. The state of the world is (or was, at least) improving, it's not just that we're creating more people in developed places. I would look deeper into it, but I really have to go to bed now.