Here's why:

* Abundance: Keratinocytes make up the vast majority of skin cells, forming the outermost layer (epidermis) and its various sublayers.

* Function: They produce keratin, a tough protein that provides skin with its protective barrier against abrasion, water loss, and pathogens.

* Renewal: Keratinocytes constantly divide and migrate upward, eventually shedding as dead cells, contributing to the skin's self-renewal process.

While other cell types like melanocytes (pigment producing), Langerhans cells (immune cells), and Merkel cells (touch receptors) are important, keratinocytes are the most numerous and essential for skin structure and function.