You literally said 'I guess the numbers have been run and since my 86 year old grandma has and can use a smartphone, that those exceptions will not as frequent as you think.'
This weekend, a QF flight I was on was cancelled at the last minute due to the aircraft going tech. The announcement over the PA system was to 'refresh your Qantas app and you'll see a new boarding pass for a new flight. If you do not have the Qantas app, please see me at the counter.' Of the ~200 people waiting at the gate, ~75 lined up to wait for the poor gate attendant to issue them with new BPs.