A pineapple plant produces only one fruit in its lifetime, but the plants are very close together, and the resulting fruits are very big, easy to pick and durable and long-lasting when shipped.
All things considered, this is a lot of fruit growing from a small ground surface area:
Depending on growing conditions, the plants are planted 0.5–2 feet apart in rows that are 2–4 feet apart with up to 65,000 plants per acre. After producing one fruit, each plant dies but generates 2–4 offsets that can be left in place to grow and fruit. Finally, after the second crop the field is tilled and the process starts over.
Rather than thinking of it in terms of fruit per plant, think of it as fruit per acre: assuming 90% success at getting a 2 pound fruit from each of 65,000 plants, 1 acre of pineapple generates 117,000 pounds of fruit (I did that math myself and field observations may vary).
A cabbage field is very similar to a pineapple field: a cabbage plant only creates one cabbage and it is harvested once per year. But cabbages are large, compact and you get a lot of them per acre. Cabbages are one of the cheapest vegetables per pound in fact, at least where I live.