Credit, today, is essential. If you don't have a credit card, it's difficult to have a credit rating. People who pay on time, but without a card, find it difficult to prove their creditworthiness. Those who owe money on a credit card at least have a history and are more likely to be accepted for further borrowing.
Nowadays, if you see an advertisement for a new car, for instance, the price stated is not for cash, but for using their company's credit agreement. The companies rely on added income from credit arrangements. Paying cash, which would actually be a bank transfer as cash couldn't legally be accepted, means that the car comes at a higher price than advertised.
In recent years, it's often been assumed that you're doing something illegal if you pay or accept cash. There are strict limits on the amount of cash you can use for a transaction and banks are obliged to report unusual activity. The term 'money laundering' is an everyday one and banks are fearful of being fined if they don't check the reason for large transactions.
I've been with my bank for over 25 years and was recently required to prove my identity. That seems ridiculous. They vetted me when I opened my account and have my history of business. They must know who I am, but are over-cautious, because banks have been found guilty of assisting money laundering. Maybe I should understand their concerns, but suggest they sort themselves out first.
Yes, there is an undeniable problem with fraudulent cash transactions and cover ups to hide the flow of money. Because of that, we are all deemed guilty until proven innocent. That seems to be the reverse of the normal legal system, which is innocent until proven guilty. It's a shame that we're put in the position where we can't trust each other, but perhaps we've brought that on ourselves by turning a blind eye to previous illegal activities. The days when cash was king have gone forever.