You're observation is very correct, most people everywhere are adopting online payments instead of the traditional cash that we have been used to, if it continues this way I believe that in the future cash payments might be phaced out. The internet has changed a lot of things especially in finance, it is very convenient to sit down in your house and buy goods online, make payments online and have it delivered to you without leaving your home. It will take time for physical money to phase out because people have been using it as a means of transactions for centuries but change is constant so due to the convenience of making payments where you don't need to be physically present, online transfers will take over in the future. If almost everybody starts to abandon carrying cash around it will die a natural death. Whether minting of currencies will cease is what I don't know but if people are no longer interested to hold it, governments will be discouraged to be minting physical currencies. If Bitcoin gains massive adoption as an alternative to fiat it will also discourage people from holding physical currencies.