Total removal of fiat from the society will do more harm than good.
No matter the level of technological development, not everyone will be able to embrace cashless transactions. And also, most services need to be paid in cash.
I agree with this, even though we are facing a crypto world in the future cash will never extinct. I think Government will always consider the situation of people, not all people can do or operate advance technology and of course not all can afford. If incase thats the case they need to educate people to learn and know how to operate gadgets and provide free internets that will never last to have access to. Even vendors must learn. But it will be a step by step process and i don't think it will let paper money extinct.