"We as a society" didn't really do this. The banks, however, really like this, because it solidifies their economic position. Imagine how much more money they'd make if everyone is required by law to make all their transactions through them.

Who do you think is trying to convince people that this is the right way to do things? How long have we associated "anonymous transactions" with terrorism etc.?

Only recently, we've developed the idea that something must be wrong with you if you use cash. $100 doesn't even afford a meal for two at a nice restaurant and people look at you like you're a drug dealer if you carry a $100 bill.