>>1943372>>1943367>>1943180>>1943160Before sewing machines it took a long time to make outfits, that's why barbaric races used mostly leather, and why it was cheaper. Time = money. It doesn't have to be nice to work.
And you don't want it to insulate, you want to not get rained on nor get ticks nor dirty from mud you lay on or sit on. You can wrap it around your whole body in a storm pretty much, aside from the boots that'd not need it. And it makes us look bigger to wild animals so they are less likely to attack.
Cloth was colder a thing to wear as it let air get through so really it's warmer even if it doesn't insulate like your imitation Eskimo gear, of which was originally made from, you know, animal skin and all.