Banks have been heavy users of ICT for a long time. From the introduction of MICR  in the 1950's through to the current push for 'Chip and PIN'.
The reason for this enthusiasm for new technology is to keep costs down. A simple estimate of the number of transactions that occur daily in the UK will explain why automation is essential!
How many people have bank accounts? - estimate 1/3 of the population... some 20 million people.
How often do they use their accounts? this is a for bill payments, holes in the wall transactions, debit cards, etc. - estimate every other day... so 10 million transactions per day.
How long does it take to handle a transaction? guess 30 seconds of human work... so 5 million minutes of work per day.
How many transactions could a worker handle in a day? based on an 8 hour day... 8 hours = 480 minutes (roughly 500 minutes...)
So how many workers would be needed to keep up with these transactions?
So around an additional 10,000 workers would be required - and these figures are underestimates.