If I remember correctly, early Android versions (or it could have been HTC specific) had a tutorial for this, as part of the new phone setup process. I guess they removed it when most buyers owned a smartphone before.
Around the time of the first iPhone, Apple also had a long video on their website (it must have been 30-60 minutes) meticulously going through and explaining every feature of the iPhone. No idea if something like that still exists.
