Because, trying to give face while jumping.
Duffle jackets are distinguished by their heavy wool material and distinct horn toggle fasteners and were initially worn by Belgian fishermen before the British Royal Navy used it to protect against the cold. In modern days, the iconic outerwear is popularised by many British musicians and the beloved Paddington Bear and over the years has become a practical and versatile staple in menswear.
Designers have reinterpreted the outerwear including using materials such as waxed cotton, printing on the fabric, bonding with contrast material and altering the silhouette but the duffle remains iconic with its toggle fasteners, deep pockets and overall utilitarian look. Owing to its functionality and style, the jacket is easy to style as much as it is easy to wear.
When you wear or invest in a duffle jacket next time, try
2) dressing it up with a button shirt and dress shoes (go from utilitarian to spiffy just like that)
3) keeping the rest of the outfit simple (let the toggles and deep pockets speak for themselves)