My parents' last 2 indoor/outdoor cats show the extremes that can be found. The last cat they owned, Hamlet, lived to be 14 so being both inside AND out did him no harm. And except for the occasional dead bird or baby bunny, HE did no harm.
BUT!!!
Ernie actually killed the neighbor's PET pigeons before we realized that het was leaving the yard. AND he dissappeared with no trace after only 3 years. We do not even know what fate befell him.