Comfort is a great factor to consider in a dining room, especially if more time is spent in the room. And a dining chair with arms is an added level of comfort in the room. Whether the chair is padded with a cushion or not the arms will provide more comfort from the regular chairs.
Chairs come in various style and textures with more than one material combined to build the chair. It can vary from a fabric padded cushion to wood, rattan or even MDF materials. There can be chairs available with the arms that are removable to store it separately. Having arms on the chair will also help to keep a laptop on it to browse or work.