As far as I can tell, it's entirely that. The things the author cites as how mobile banking supplanted going to the bank (paying for things with debit cards, getting your paycheck direct deposited, etc) have nothing to do with mobile banking. They are all just as you said: we live in an increasingly cashless society, the only reason to go to the branch is to deposit or withdraw money, so the need for tellers has gone off a cliff.