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

Think of all the things you are hitting with it: decks, fence, downspouts, siding, trees. These things can resist the plastic string but would get absolutely destroyed by a metal wire on a weedeater.

That being said, if you are just trying to take down some thick vegetation with small tree saplings and no structures to be destroyed, you can get metal blades to help get the job done.