Why did World War 1 soldiers were capes?

World War I soldiers wore capes primarily for added protection against the elements, such as rain and cold weather, while also serving as a practical garment for movement. The design allowed for ease of wear over uniforms and could be utilized for various purposes, including as a blanket or for camouflage. Additionally, capes were lightweight and could be easily packed, making them suitable for the mobile warfare of the time.