The "sustainable" and "environment friendly" choice for headphones are wired headphones that are built like a brick. A good pair will last basically forever. Of course that isn't the market these headphones are in, but that's also the problem. New bluetooth standard? New advances in noise-cancellation? You won't get them. Even if these headphones are great (which I doubt) they're still destined for the garbage heap.…
But ultimately this means, as long as I don't lose them I can repair/replace the wire as needed.