Right now I would say Fiat is more important for daily usage as Bitcoin hasn't been widely adopted yet and cannot be used as a medium of transfer in all place but that may change in the future.
Everyone's opinion will be to choose FIAT over Bitcoins.
The main reason for this is the high volatility of Bitcoins.
As Bitcoins Don't have a fix price so many people won't like to use it for daily to daily use.
Moreover Bitcoins can be treated as assets which can be stored and profits can be yield from it.
Hope you get this Op.