I don't think that the scarcity of Bitcoin makes it a very good store of value. As a matter of fact, at this moment, I do not consider Bitcoin as a reliable store of value due to its high volatility. It is also one of the reasons why Bitcoin is having difficulty getting the acknowledgment of the authority of being money despite Bitcoin actually being money.
It's because most people seem to want a non-volatile asset when talking about store of value assets, rather than an asset that has long-term appreciation. Hence why a lot of people look at gold as a "store of value" — because it's a lot less volatile despite it performing like crap throughout the years.