They acknowledge what we already know. iOS updates irreversibly impact battery life.
iOS 26 is so poorly optimised that the 17 Pro Max has worse battery life than the 16 Pro Max and 16 Plus when the latter two run iOS 18. For the first time ever, the latest iPhone on its original iOS version with a larger battery loses to the previous model due to an original iOS version’s inefficiency.
iOS 26 may be improved so as to improve battery life for the 17 series, but do NOT be mistaken: iOS 26 will NEVER match iOS 18 for any other iPhone, not even the 16 series.