In 5e D&D, do Noble Genies suffer the side effects of wishes?

In the Monster Manual, there is an optional rule for genies, one to allow the wish-granting kind. In accordance with legends, and the way that the text describes it, surely these genies aren’t risking losing the spell every time they grant a wish, right? Or else, why would a genie ever agree to grant a wish? (unless they only ever copied an 8th level spell or bellow)