But that doesn't necessarily mean that cash will go away, I think people are attached to cash a lot and it's a different feeling when you have cash.
In my opinion, your opinion is true. Why ? Indeed, cryptocurrency is now much interested, some people consider cryptocurrency as a valuable asset to them. but cryptocurrency has one weakness that is not the official currency. cryptocurrency is just a virtual currency in the digital world. so this is where another function of cash is to be a medium of exchange for cryptocurrency, so the selling value of cryptocurrency can be used for in the real world.
The economic system is not always going up, there are some times, like Ukraine right now, they are hardly taking an economic state right now, they are also increasing the country debt as well as struggling with money system.