I think BTC will work best as digital gold. It also is what will allow it to continue to avoid the ire of regulators. If bitcoin were to become widely used as a currency it will face a lot of pushback from governments. Not saying it couldn't succeed in that role, but it would be rocky. If it instead replaces gold as a hedge against inflation and a safe haven store of value in portfolios, it will exist quit nicely and has runway up to about 30x the current levels if it just works as a store of value.