If the FBI simply wanted into this specific phone there exist companies that will do it, right now. Even high-end hardware security modules are not rated again

If the FBI simply wanted into this specific phone there exist companies that will do it, right now. Even high-end hardware security modules are not rated against a competent attacker with unlimited resources, in physical control of the module, who can attack it destructively. In fact, they must largely know there isn't any really important evidence on the phone so they have time to play these games.