Why do weed whackers/weed eaters often use plastic string and not metal wire?

Question

Why do weed whackers/weed eaters often use plastic string and not metal wire?

In: Other

Answer 1

Ever hit yourself with the string?

It hurts, but it doesn’t do any real damage.

Now imagine what would happen if you inadvertently hit yourself in the ankle with a metal wire spinning at that speed?

I see the commercial for the string trimmer attachment that looks like it’s made of barbed wire and I can’t nope away quick enough.