Because it needs to become a store of value before a medium of exchange. cart before horse. What percentage of the world uses it as a store of value?
that is not true
if it wasn't, then how did whiskey and rum become moneys at certain times, and why is tobacco a currency in prisons where money is forbidden these are emergent moneys that were adopted out of need for a money, that used stores of value (all durable goods are inherently a store of value)
bitcoin was a great MoE in the silkroad days, when arguably it was more important as a MoE than SoV. as long as bitcoin is worth >$0, it can be used as money, it does not need to be worth more to do this. but bitcoin is rarely used as money anymore.
well, in those days the payment use case was more viable due to the relatively low transaction demand thus the expensive use case, payment, was viable this is now becoming unviable and shitcoinery is making it more unviable, but we have LN and ecash to help shift payments off chain without weakening the security of the base layer
in this respect, bitcoin's evolution is a bit different from most kinds of commodity money because it is also an accounting system