system
Given the following post, respond as if you're commenting on Reddit:
human
[Avatar: The Last Airbender] Why does Toph always need to physically touch metal to bend it?
gpt
She did at first because it was a brand new technique and she was learning and figuring things out as she went along. As she got better at it she was able to do it from farther and farther away. 

By the time of Sozin's Comet she could do it from several feet away - she was able to tear a metal panel from a wall in an airship to stop a firebender soldier. A year later and she was good enough to bend weapons in people's hands and pull the screws and bolts from the wheels of a Fire Nation tank from a distance. When she took on her first students she specifically taught them to metalbend from a distance right from the start. At that point she said that as long as she could 'see' the metal, she could bend it just like earth.