At this stage bitcoints not so popular as the dollar. But its popularity is growing. By dollar just all become accustomed. A cryptocurrency a relatively new and many people do not trust it
People massively using the US Dollar doesn't mean it's more or less popular than currencies such as Bitcoin.
They use it because there is no other option than that in their daily lives.
I don't ever think people (non Bitcoiners) will fully trust or believe in Bitcoin as a currency since
there is no central authorityPeople should not unreservedly trust or believe in Bitcoin, they just need to trust or believe in their "central authority" (aka government) a little bit less than they would in respect to Bitcoin. There is no way back after they lose that bit of extra faith they might have. And I have a strong inclination to think that a central authority has much higher chances to
deliberately cheat or scam on folks than a decentralized one. So it is just a matter of time...
But once bitten, twice shy