> destroys his mitochondria Fine print: only the father’s. Maternal mitochondria from the egg are dormant at first and activated after 10 (?) cell divisions. Those mitochondria are never reset, and return to dormant state as soon as specialization into egg cells allows them, afaik.

Notwithstanding heteroplasmic (paternal) mitochondria making it into the cell in 8% of cases, with unknown effects.