system
Given the following post, respond as if you're commenting on Reddit:
human
[MCU] Thanos states that half of all living creatures in the universe would cease to exist after the snap, so why does bucky’s metal arm and falcon’s metal wings bite the dust ?
gpt
Everyone's clothes went with them too. Items worn by a sapient creature were apparently considered a part of them as far as the infinity stones were concerned. 

It kinda makes sense that whatever magic the stones used would do something like that, since a lot of natural parts of our body are also dead matter. Like if you make a person disappear, does their hair go too? It's just dead keratin protruding from your body, and isn't really a part of you any more than an artificial article of clothing.