I was curious since its an old clothing technology
Puttees are leg wrappings used in ancient China, made it's way to India (or vice versa) and the English occupiers noticed and integrated it into their uniforms for Asia and Africa. It then spread to nearly all European powers in time for the WW1 conflict.
Benefits:
* helps prevent dirt and bugs getting in * rain, mud and high-snow protection * protects the pants from being caught and torn by underbrush * some body heat retention added * a layer of cut protection from sharp rocks. * provides leg compression to avoid pooling of body fluid on long marches.
The list of reasons is why it was adopted by the militaries around the world since it was just a piece of fabric (e.g. durable wool) that was one-size fits all and was effective in many ways.
There were different ways of wrapping them to introduce interesting patterns that stop them from loosening if you don't want to wear them tight.
I may give this a try if I suspect a more wild trail ahead.