I think the general answer in short is yes but, ultimately the value proposition is dependent on your use/needs. As you describe your commute it certainly doesn't seem like bike specific outer wear is a necessity.

Over many years I invested in a lot of bike specific clothing that I use for all different types of weather and riding that I do. I prefer these garments because they have features that add efficiency and comfort to the riding experience. Outer wear have features such as long sleeves and tails, ventilation, reflective materials and colors, strategic pockets, waterproof or wind blocking abilities and these are all just tools in the tool box that help me get the job done every day all year more comfortably.