Might be a stretch, but it could be nice to be able to reference or include other recipes in the ingredients of another recipe.
For example:
A cake that specifies frosting, being able to select my favorite frosting recipe to be used.
Or in a recipe that calls for 1 cup butternut squash puree, referencing 1 cup homemade butternut squash puree from a different recipe.
This way each component can easily be accessed from the "main dish" recipe. In addition, the nutrients of this combined recipe could be more accurate when composed of other recipes as 1 cup canned butternut squash may have different nutrient values than homemade ones.