Having less in the US means you have a hard time paying your bills, etc.
Having less in a third world country means you're dying because you're literally crapping your insides out because there's no drinkable water.
Eliminating poverty (especially extreme) poverty seems worthwhile . Making sure everyone has the same amount of stuff doesn't seem quite as important
Yes, there are a lot of programs to provide help in the US but many of them are far enough away that you'd need a car and if you don't have a car you are out of luck.
I'd argue though that in North America, outright starvation isn't as much of a problem as just having difficulty accessing healthy food. The last stats that I read argue that about 15 million kids in the US experience hunger. They may not be starving, but they will have more trouble learning without adequate adequate nutrition.
That said, that has a LOT to do with our guidelines via the FDA and draws down from that moreso than inequality.