Money earned from the internet is known as digital/electronic money.
People who earn money from the internet, they get paid money in electronic form by payment processors such as skrill, perfectmoney, alipay, paypal, bank-wire transfers because online workers are worldwide.
How is digital money is your country ?? Bitcoin is a part of digital money.
If that will be the era of rye digital money of course that is what will happen but that will be decades from now but they are starting because of the cryptocurrency. And the people are starting to cope up with the digital thing rather than cash. Nevause it is more convenient and they are handy. They are much safer for me. And yes the cash will extinct because before we have cash we have golds as our money and they are not used anymore and that is what will happen to cash.