And cow feed is also grown with tons of pesticides and you need much more of it for less tissue at the end.

I have hard time seeing clothing with a bigger environmental than leather.

But one could also use linen, hemp, ramie/urtica/nettle. However, they are more complicated to process and as the results are textiles, they are not windproof or water repellent.

Organic and recycled cotton is a lot better, and hemp and linen are also pretty good. And if you're worried about hazardous pesticides the majority is used while growing feed for animals.

The tanning process is no joke either.