An attacker during research would root the device anyways and find any crash conditions even better than shutdown.log. 99.999% users will not root. So this targets users.
It is quite difficult to jailbreak any recent iOS device. To the best of my knowledge, the last jailbroken SoC was the A12 and there haven’t been publicly known jailbreaks since then.
That’s not to say private methods don’t exist but none seem to have been documented as used in the wild at least.
