The digital economy will likely be used extensively in the next 50 years, and coin derivatives with large technology infrastructure will be used as legal funds. It would be possible to raise a generation that would not know what banknotes and shillin money would be for many years to think, nor would it be a lie or a great claim.
Paper money will still be around in some form, we tend to think that technology will always move forward but there are many challenges in the future that need to be solved and there are many countries and places on the planet where the electricity or the Internet are not present in fact there are several hundreds of millions of people without direct access to water, as you can see the challenges are huge and while the digital economy will become common in the first world I'm not so sure about the third world.