1. I didnt conpare an iPhone to anything.You’re missing the point.
Comparing an iPhone to a single use machine isn’t a good comparison.
Airline avionics are really reliable.
Also, in this case it’s “or”, not “and”
2. Your comparisons are bad.
3. Avionics have backups because they understand things can and will fail.
Where is the backup here? ... from what I see, it either works or it doesn't.