True, central banks can make their fiat work efficiently in their local regions but will never make it work efficiently for international trades or remittances. That’s why bitcoin will always have an upper hand over fiat.
If enough people use it for that, they may eventually start to complain that it's so hard to use at the grocery store. That was my path, so it's the one I always think about, first.
I think people are initially scared of this technology. But when more and more people start using it, they realize it’s way easier to use it than fiat. Like it’s so tough to open a bank account now and with CBDCs, they are gonna add more friction to it, meanwhile a 10 year old can just download a lightning wallet and start sending and receiving money. And with time the UX/UI are gonna improve more dramatically.