Not surprising. The area in the circle has more arable land (land where food can be grown) multiple times more than the rest of the world, combined.
Source please.
That more-than-half number didn’t seem quite right, but India and China are joined by other very populous states such as Indonesia and Bangladesh, etc. The arable land claim I’m not too sure about, because there has been a lot of dessication and desertification in both India and China, but for example in N America the bulk of the arable land is east of the Rockies, and a good bit is technically arable but too cold to support agriculture. Nearly half of Africa is the Sahara, so despite the productivity of the ribbon of arable land along the Nile and some other rivers, not much there. Australia’s arable land is mostly in the SE. South America is similar to North America, arable land east of the Andes, and much of that is not cultivated, although it is fertile enough (and well-watered) to support modern agriculture. Slash and burn methods have been used with consistent success in the wet-dry tropics for millennia.