This whole thing seems like green-washing from Apple. Yes, they have now removed some CO2 footprint from their products, but they haven't actually reduced the CO2 from being released.
As a (world) society, we need to eat less meat and especially beef. Cows release a lot of methane (worse than CO2), use up a lot of land and water - and for that those last two don't forget the land and water needed to grow the corn that is fed to cattle in North America. Yes, leather is a byproduct of the cow, but as has been stated above, it keeps the price of the meet down. If leather usage dropped, there would be less revenue per cow so meat prices would have to rise which would lead to less meat being consumed.
There are lots of people doing mental gymnastics, passing off leather as a byproduct or sustainable. It isn't. Just come out and state that you like leather and/or beef rather than trying to convince others (and likely yourself) that industrial cattle farming isn't harming the environment and contributing to climate change.
