You mine for it, same for precious metals.
I know currency is subjective as we know it, does that mean it's not any more flawed? Before we had these currencies people used sticks and other ledgers to measure value. Currency purports itself as a measure of value, as a metric it abides in the same principles as every other metric, standards recognized everywhere no matter the time, and so you cannot inflate a ruler, no matter how many rulers there are they all measure the same thing.
Simply because there is no examples of currency in today's world which is Stable doesn't mean that currency shouldn't be stable. It most certainly cannot be both a measure of value AND a store of value, otherwise it is only commodity, is it not?
I suggest you go down the rabbit hole.
You mine for it, but that doesn't mean it relies on the idea that value spent is value stored. That doesn't follow. Precious metals have value because people see them as valuable, and it's the same with Bitcoin.
I'm willing to consider what you're saying, but I find it very difficult to imagine what you're describing.
A good currency should have stability, yes, and bitcoin has gained more stability over time. However, it would be very difficult for a currency to retain exactly the same amount of value, with one pound always and everywhere buying 10 loaves of bread, ten pounds always buying a ladder or something like that. Is that the kind of thing you're describing, or have I misunderstood.
I have no problem with currency being both a measure of value and a store of value, though obviously it's an imperfect measure of value because of the factors I've mentioned. I'd say all forms of money are commodities in some sense.