In that case lots of people will be doomed, especially the ones who knows nothing about it existence, and the negligent ones, this set are aware of it existence but do not care about venturing into the system.
A time will come when cryptocurrency will surely be a must for survival, but before then I believe the world at large will be ready for the journey and adapt to the new process when it finally approaches.
Yeah that would be the situation happen since if that scenario happen those who can't adopt will not survive.
That's why even by now people need to learn new things and became more adoptive with current booming of other digital financial stuff.
Since if they really only on fiat for sure nothing will happen in their future. Its like they are one step closer to get bankrupt especially if they can adopt immediately on future changes that might happen. Bitcoin and crypto is the future so people should learn on how they could get lots of opportunities on this so that they can help their selves to grow.