Many make this point:

PETA says that a Mercedes car made with faux leather
“saves” half a dozen cows. Apart from violating the
separation between cattle and state, there is a
problem here.
Aren’t the cows being slaughtered anyway, for meat?
It’s not as though the leather from meat cows is
always wasted, or the meat from leather cows is always
wasted. Every part of the cow that can be used, is
used.
The number of cows saved, even if every Mercedes had
no leather, would be roughly zero.