but whether when adoption happens they will use it. or they are more comfortable using FIAT.
I think it depends on what they need but for now some people including me it's much comfort when using Fiat for daily needs but for some digital transactions i prefer Crypto and beside that it's have some scalability problem and compex things comparing to Fiat where you just can get the cash and buy everything so it's still a long journey for crypto.
stablecoins issued by your country's central bank, or mainstream crypto coins like bitcoin.
There already some example out there like China or Turk with upcoming CBDC, Digital lyra or yuan beside that as you can see ecuador with bitcoin as an legal tender but still need some time to see the full efect of crypto especially bitcoin.