Of course, cash can be dirty and even carry viruses and bacteria. I have heard that some people put their newly received money in a small plastic bag and do not touch those paper notes for two days. Viruses cannot stay alive for too long without infecting the next human, so the cash eventually cleans itself of such organisms.

It is true that due to the coronavirus pandemic, most shoppers have changed their minds and decided to use contactless bank cards more widely, as well as increased the volume of their E-money transactions, but some people still prefer traditionally pay for goods and services in cash just to maintain privacy.

As of Bitcoin, some gateway platforms (such as BitPay, WePay, etc) allow their verified customers to easily make and automatically accept cryptocurrency payments. In fact, these companies simply convert the deposited coins to fiat money on the request of the customer. I think this payment method can also be considered modern.