Of course you’ve only noticed it in people of colour. How would you be able to see it on a white woman? Everyone has it, it’s just more visible on darker skin obviously. Likely due to the skin rubbing/chafing against each other when walking
Sorry, to be clear I'm talking about witnessing it in person and there being the accompanying dryness/roughness to touch. To be fair I haven't seen many new, different Euro Caucasians this past year but there hasn't been proportionately as much dry/rough skin. On Latinas, SE Asians and Chinese again the proportion with dry/rough skin has been lower but not zero.
Luck of draw perhaps, I wasn't avoiding or visiting based on "presence of greyness" in pics.