I think the appropriate title will be what is stopping BTC to use on daily basis based on the context you are proposed in you replies of this thread.
What stop me from using bitcoin is I can't find stores which accepts bitcoin rather than USD. i would love to see signs in the shop like BTC accepted here, government didn't made bitcoin as legal tender so its also not easy for the shops to accept it as which literally means government is stopping us from using BTC on a daily needs.
In the US, there are 30K websites that accept bitcoins. According to me, there is a gap in the protocol. What exactly, I'm not sure. awaiting your excellent responses.
It can even be 100K websites but as you asked why we are not using BTC as regular currency like our bills the reason I mentioned is clear we are lacking the physical stores from accepting BTC.
Even now you can almost spent BTC on any website by converting it into gift cards and use the gift card to buy on any website but its more complicated when someone who is using fiat so they won't be convinced to use BTC instead of Fiat.