Why don't folk guitars have steel bars?

Folk guitar can't live without steel bars. Because the strings are tensioned to bear a force of 90KG (standard pitch), guitars of the same quality will also have steel bars. There are no steel bars, only classical guitars. Because of its low bearing capacity, there is no need for steel bars. Practicing the piano is not strengthened, because it is very common in classical folk songs (some are strengthened, but few). If there are no ribs in your hole, see if there are any on your head. Usually, there are three screws covered with plastic plates. If it is still not reinforced, your piano is really garbage in the garbage. The neck of a folk guitar without steel bars can't bear the huge tension, it will be severely deformed and bent, and finally it will be burned into firewood.