You see the "super-simplified" at the beginning of the explanation? So, no. Neither does that explanation account for overconsumption, food waste & spoilage,

You see the "super-simplified" at the beginning of the explanation? So, no. Neither does that explanation account for overconsumption, food waste & spoilage, crop mixes, erosion & desertification, water supply shifts, etc... It's a very basic upper bound. The number of people who could be fed in the best case.