The cleansing agents in soap are too harsh for dry skin.
A typical bar of soap will strip your skin of natural oils and disrupt the delicate pH balance, damaging your skin’s protective barrier. This can cause more dryness and irritation.
And when your skin is overly dry and flaky, it leads to premature fine lines and wrinkles forming.
Even the mildest soap is going to be too harsh and drying for your face.
Whereas a good face wash will work with your skin, without stripping away essential oils and drying it out.