I view side orders as a crucial part of a restaurant menu. A good selection of seasonal vegetables, including a few different potato dishes, helps keep the menu interesting and allows customers to choose what they fancy. Of course it’s important that the sides on the menu are suitable accompaniments for the main dishes on offer.
Some restaurants don’t offer a choice of side dishes on the menu at all; instead serving up a random assortment of vegetables that are not always appropriate to the main dish ordered. This doesn’t make any sense to me.