These promises are not of a cure-all or a magic wand, but the industry can and does offer products which help your skin resist environmental damage and the effects of aging. If you were to see the skin of an elderly person who had been secluded indoors all his life, you would notice the effects of gravity, that is some sagging and the folds that go with it, but no wrinkles, thickening of the skin, or discoloration. His skin would be baby soft. Most of what we think of as inevitable aging comes from the sun and pollutants. We can also take reasonable care of our skin by keeping it clean and hydrated.
Oily skin tends to be thick and resilient, while dry skin can be thin and sensitive.
A temporary condition of the skin is its relative hydration. The cleanser is different from a bar of soap in that the soap by definition is alkaline, and your skin is naturally slightly acidic. Your skin comes out potentially dry, dehydrated, and at risk to infection. Acne is an example of a common skin infection. A professional cleanser, on the other hand, is at or close to the skin's own pH, which is slightly acidic.