Bikepacking??? Simpler is better IMHO. And light as possible.
Myself I go with 2x10 drivetrains because...
- Relatively inexpensive (Deore XT derailleurs and XTR shifters)
- Replacement components are readily available at most bike shops if needed.
- You get good separation of ratios when grinding up hills for the 5th day in a row.
Brakes? Always cable Avid BB7.
DI2??? I do not want to get out in the middle of nowhere and end up with a dead battery.