Nearly everyone wears cotton or synthetics, no one "needs" wool the same way you don't need the unique light a whale oil lamp gives. These are, again, vanities for the vain at the cost of animal suffering. Wool is also very expensive and the environmental cost of raising all these animals outweighs the biodegradable benefits.

Except in reality, leather is more or less a fast fashion item that comes and goes. People buy them and toss them as their fashion tastes dictate, again, its not the 17th century. Its very rare to have a leather coat you wear daily for decades. Even in poorer countries is expensive to get and treated mostly like a vanity item. Alternative fabrics and materials work just as well and they both end up in a landfill after a few years anyway. Also the leather industry is abusive and exploitative towards workers and exposes some of the most vulnerable people to carcinogens and poisons needed to "work" leather. Is your vanity item worth all this suffering?