What amazes me is watching Delta specifically on several occasions their crew management system seems to be a huge weakness. Once it goes down it seems to heavily rely on crews calling in to note where they are and other status details.

It's like once it goes down all state is lost and for a long time, often days, crews describe having to call in and wait while they figure it out who does what / goes where.

I don't like to oversimplify, but it really seems like a solvable problem ...