I don't _need_ it but using a smartphone instead of navigating via a physical map and taking photos of memorable events throughout the day sure is nice.
The car has a map + navigation already, and I care very little about documenting events... although I do use the phone during tear downs for the purpose. Still the prime use of the (my) phone is actual phone calls.
I gave up my smartphone a decade ago. It's only "inconvenient" when people expect me to have internet in my pocket.