This very title tells of the times we live in. I would like you to imagine a title for a lecture eighty years hence: "Why digest food?" I leave it to the reader to imagine -- or think of -- the technology already with us; and the 'scientific advance' and its practicalities, including the resultant apparatus ending in tubes with needles and switches in every house. Also the successful propaganda denigrating the "merely biological" conception of eating and the hostility -- known to have prevailed in the Catholic church for many centuries -- towards its pleasure and thereby towards its spiritual meaningfulness and civilized quality. As whole peoples in our time have regarded feeding their babies at the breast as something rather for savages, so might people of the future regard nourishment by digesting the lovely food we eat in the same way.
Don't think it inconceivable. The human race is a fallen race. It has fits of madness, sometimes merely local, sometimes nearly global....
G. E. M. Anscombe, "Why Have Children?", Proceedings of the American Catholic Philosophical Association, Volume 63 (1989), pg. 48.