>>1871177They designed them for expediency not necessarily efficiency though.
I've been thinking of giving a tighter constructed something like this a shot for winter and it's foul weather. Cheap, simple,easily replaced, and still fairly durable I'd imagine.
>https://weburbanist.com/2012/08/01/single-step-slippers-made-of-one-shoelace-strip-of-felt/