If I remember correctly, in contrast to WTI, you will get assigned a shipping/warehouse certificate for wheat/corn in a designated elevator somewhere. You'll have to pay the warehouse a daily carry cost but don't actually have to take it out of that warehouse (you can if you want to).
Currently, speculators make up roughly 2/3rds of the outstanding WTI contracts [1].
In most commodities contracts taking/making physical delivery by physical players is rare. The physical delivery option is there to make sure that the underlying commodity market and the futures market converge; and you don't need someone to actually deliver to make that happen. The threat of delivery/taking delivery is usually enough.
One thing that is not mentioned in the article is the massive amount of soy beans that China imports each year (approximately 90 mmt in 2019) to produce feedstock for their hog herds and acquacultures. Most of the soy beans are imported from the US (pre trade war), Brazil and Argentina.