On the other hand, a store of value, high fluctuation in value makes it unsuitable to be a store of value.
How so? I have been using Bitcoin as store of value for years, and it worked out pretty well.
People think just because of the fluctuations that Bitcoin isn't suitable as store of value, but why would you bother caring about short term fluctuations when the price is bound to increase throughout the forthcoming years? If you park your money in Bitcoin for a couple of years, why are current fluctuations a problem? You are not speculating, you are not planning to use any of it, you just want it to grow as time goes by, that's what a store of value should function as.
Most legacy means of value storage have time on time proven to be unreliable in that aspect. Bitcoin has been and still is the ultimate store of value of this century.