Watched The Hunted (2003) the other day , an action-thriller starring Tommy Lee Jones and Benecio del Toro. It was filmed in the Pacific Northwest, in and around Portland actually. A scene came up where Tommy Lee is tracking Benecio in the woods and discoversthis footprint. Definitely harder to spot than one with regular tread marks.
He wore a size 10 shoe with no tread. Almost like a slipper. Kinda like this one.
In other words it's a tracker moccasin designed for quiet steps while stalking animals. Or if you're on the run, could come in handy lol. Anyhow, the execution in concept and function is inspiring.