Do dead cells matter for the functioning of multicellular organisms?

Dead cells are of great importance for multicellular organisms. In some species, dead cells in the outer layer of the skin form scales, which serve to maintain body temperature and constant skin moisture. This is typical for many reptiles. In other living organisms, dead cells form a stratum corneum, which is a kind of armor and serves to protect against enemies. This is typical, for example, of turtles, their shell is very hard and impenetrable for many predators.