Plants have many potential uses, of which a pleasing appearance is one. However, one plant can serve many purposes, and to choose a plant purely for ornamental purposes is a wasted opportunity - losing the potential production of fruits, vegetables, shade, windbreak or other benefits.
Note that many food plants are very attractive, especially when lush and well tended. There are many edible flowers for example, including large and showy ones such as dahlias.
In a time of crisis, and to build resilience at all times, it makes sense to choose only plants with [multiple uses.