Why do identification documents have expiration dates?

I noticed that quite a lot of countries enforce expiration dates for their IDs, and according to Wikipedia, they seem to be valid for 10 years in many countries.

I figure that limiting the validity of an ID ensures that people have to "regularly" contact agencies and allows to update the picture, but I cannot really figure out why it seems to be the norm.

Why do many countries set expiration dates for the identification documents they issue?