In my opinion, Bitcoin is a store of value, not a currency. There may be cryptocurrencies becoming legal tender, but not now, volatility and supply and demand need to be considered.
If I’m given the option to pay with Bitcoin I don’t think I’m going to pay with it, I’m still going to continue making payments with Fiat. Everybody’s opinion differs, there are people who really wants to be able to be making payments of whatever they are buying with Bitcoin, but that's not me. I also consider Bitcoin as an asset just like you have said,and not a currency.
The only thing I know that I can be able to use it for is for some daily transactions that I make, that is only with friends who are also into Bitcoin and whenever I want to exchange with them or something like that. This is not something I do steady, it maybe just once in a month, because I mostly want to Hodl my coins.