Chaosmancer
Legend
Didn't say that other people couldn't grow the stuff for consumption and trade. But trade rewards efficient allocation of resources. Growing a diverse set of plants on a single plot of land best suited for one crop is generally a poor use of that land if your goal is to make a profit through trade. Without the profit drive, as long as you get enough of what you want, you've cleared the bar.
Thus profit farmer - less variety, more money (more problems) vs. Enjoyment farmer, more variety, less money (fewer problems).
Right... you realize there is more than one farm in a village right?
Or is your argument that entire villages of humans would grow a large amount of a single crop, then trade that crop to other human villages who did the same thing, for money.
But halfling villages would grow a smaller number of multiple crops, so they don't have to spend money to get anything they don't have.
While, yes, that is how cash crops worked, that really didn't become a norm until something like the 1700s. Far past when we generally think of DnD taking place. Because it really only worked with very large numbers of distant communities. A small village would grow everything to trade only with other local villages, generally through a central town for ease of meeting up. So if a halfling village could easily grow enough food and spices and enough goods for trade... then so could the human villages.