pH of our skin is slightly acidic i.e around 5-5.5. Products that have pH closer to skin are more delicate on skin and doesn’t make them dry. If we compare Soaps with Shower gels, usually soaps have higher pH i.e around 7-8 that makes soaps better foaming but harsher to skin.
Body wash, that too “Sulphate free body washes” have a pH closer to skin and has milder surfactant that makes them better suitable for skin. It will not make the skin dry after shower and leaves the skin soft and supple.