I think that there is very low adoption level at the moment. People (even those who have btc) trust btc less than fiat currencies, since they can't buy anything without converting crypto to fiat. And if it was possible to buy everything directly with crypto, then there could be legal issues, which would discourage people from using crypto. One of such problems is legal status of crypto transactions. There are no legal approvals of crypto deals... If its a payment for a cup of coffee, then ok, but if is a purchase of a house, then it is not a good idea to pay money and settle in a house, which is oficially "not purchased"... And if it was fully legal, then crypto would be nothing different than usual fiat money....