Calvin, Ditto what GreenFin said - hundreds of other edible varieties, all of which are not Cavendish. The tropical fruit growers I knew in So. FL grew dozens of different varieties of fruiting bananas - all edible. I'm sure Jon can attest similarly.
Cavendish just happened to be selected, long ago, as one of the best commercial varieties = ships well, has a long shelf life, and responds well to ripening when gassed. I have no explanation for what that banana breeder might have said. I think he was briefly featured in that "Fruit Hunters" doc. Only thing I recall him saying was that the Cavendish plants had to be meticulously hand pollinated and even then it took a lot of bananas to provide only a few seeds to experiment with (going for a replacement for the current Cavendish) .
One of the few banana varieties I was able to get to fruit on my property in Fl was a small, very sweet banana. Had a very good flavor but was just a little more fibrous than Cavendish. Can't recall what var it was.