I mean, I wouldn’t trust a literal iPad, but I’m not sure if I distrust an entirely figurative iPad.
It is generally faster to communicate orally and process communication aurally than by text message when the message is short enough and requires immediate attention. This is also why urgent alarms (such as those provided by the Gound Proximity Warning System (GPWS) or Traffic Collision Avoidance System[1] (TCAS) have such a component). Some stall prevention systems are even partially tactile based (making a pretty unmistakable shaking feeling (it is loud as well)).
It is incredibly slow to type and then process that visual information. In addition, it's also just much more reliable.
For time critical situations, it's not a viable option.
[1]: Yes, TCAS has a visual component and many alarms do too, but the RAs are auditory and give specific, to the point, instructions on what to do ("climb", "descend").
I also note that the budget isn't infinite nor do these aircraft like running electron apps.
Also note that not all (if not most) aircraft are not brand new and so would need all to be retrofitted and re-rerated w/ any new system and every single pilot retrained.
This requirement also includes systems for general aviation pilots and both to be able to sync with each other.
Ah yes, I forgot, we never introduce new aircraft technology because it's too hard. Too bad we don't, it would be great to fit aircraft, with, say, anti-collision transponders and advanced ground proximity systems. Oh well, my mistake for even bringing it up.
