Konstantin It's main advantage is its premium look and feel. I think it is a bit less sustainable on the other hand, since manufacturing a card from stainless steel costs more resources than a plastic one.
My other (traditional) bank only uses recycled PVC for cards and their validity period is 6 years too (like the bunq metal card).
Maybe that is something bunq cam learn from the traditional players: use recycled material and long validity periods!
