[multjoy]

This sort of imagery is often created for profit - either for the kudos of being the creator of first-generation material or for actual profit in the case of a number of asian abuse rings.

So yes, demand reduction will reduce actual instances of rape and sexual abuse - while there is an argument that nonces will nonce regardless, the encouragement and egging on by others is a significant driver of offending.

There is also the matter that mere possession of these images is also a criminal offence.