Soap-and-water is alkaline, and temporarily destroys the weak acid mantle that gives the skin some protection against infection. This is normally replaced within half an hour, but the need to do so twice a day, every day constitutes a mild but continuing stress on the skin. Edwardian ladies were warned not to wash their faces with highly scented or coloured soaps, and that is still good advice.
The more unnecessary additives a product contains, the more likely a sensitive-skinned or allergy-prone person is to react badly to it. The subject of whether synthetic dyes in foods and toiletries have any long-term effects on general health is so fraught with doubts and fears that the world-wide tendency is to phase them out.