Earlier quoted context omitted.
Do you still live with your parents or rent from a slum lord who only takes cash? Most landlords seem to only take cash or checks, it's really only the national apartment companies that take online payments.
Australia, pretty much everyone accepts BPay which is an online direct payment system or direct bank to bank transfers. These both take < 3 business days
It's a significant burden on commerce, businesses, and individuals to be without their funds for that long. And a big win for greedy banks who boost their balance sheets and profits by holding all those "in transit" funds.
In the UK, the "Faster" payment system, introduced about 10 years ago, means that the vast majority of bank-to-bank funds transfers are completed instantly.