It's not the standard of care, a doctor said it SHOULD be standard of care. Transplants for nonvital organs are very rare. It has been possible to transplant things like arms and legs for a long time- see Guðmundur Felix Grétarsson, who is able to feel things in his arms now and use them for light tasks.
https://en.wikipedia.org/wiki/Gu%C3%B0mundur_Felix_Gr%C3%A9t...
But maybe 100 people total have transplanted arms. They are rare because insurance doesn't cover them; medically they're considered investigational. Growing nerves back is still a complete crapshoot, and you'll certainly never get back normal function.
That's a pretty significant issue, because even arm transplants compromise your life in new and terrible ways. You're required to take prednisone, ciclosporin etc for the rest of your life. You trade off one crippling disability for another- a massively compromised immune system. Potentially that can kill you, if you get sick and are unlucky.
You can open a door and use a broom with a hook. You get very little quality of life from feeling tingles in your elbow. Is that worth risking your life and taking expensive steroids every day which can drastically change the way you think and feel? Probably not.
Is it worth it to be able to hold hands with your wife? To be able to feel the heat of a coffee mug? To not need help putting your arms on? Medical literature does not typically value those things. Objectively they're small, momentary inconveniences. Many, many people are happy without them. They might mean the world to others.
In cases like the OP it's cut and dry, IMO. Look at him (image fairly disturbing): https://static.scientificamerican.com/sciam/assets/Image/202...
That tissue on his face, even after 50+ surgeries, is agonizing. There just isn't enough skin and what's left is fragile. Cuts and blisters get pulled open and don't want to heal. Every movement sucks. That person would not mind wearing someone elses face; they aren't wearing their own face any more. It's completely unsurprising that their quality of life is improved, even with all the immunosupressants.