how will people adapt change from FIAT CURRENCY to DIGITAL CURRENCY like BITCOIN?

This is nothing new, the fiat to digital transition has been done for a long time. But if the transition of fiat money to Bitcoin in my opinion has not been realized because some people still depend on paper money, they consider Bitcoin as an opportunity to earn money only. Even if it happens it will take a long time to make it happen. but it can happen in the future.