Robbing a bank is stupid, too much security and too many witnesses.
You rob the small armored cars that refill ATM machines at the mall. During xmas time, the ones here carry MILLIONS, with only 2 security guards. Think of it this way: each "cassette" in the machine carries 40K in cash, and each machine holds multiple cassettes. Do the math.
Plus, those guys are lightly armed, and most only have revolvers at that.