As I've said before Bitcoin is absolutely a garbage "store of value". It's not going to exist for decades, let alone for centuries, because of the nature of technology. As you yourself have pointed out there's nothing inherent about Bitcoin other than a network effect that's made it a brand. It isn't backed and guaranteed by a government, there are no organization that are demanding to be paid only in Bitcoin as America demands to be paid only in dollars.
Furthermore There will be better technologies that will emerge and supplant Bitcoin. Land, Dollar, precious metals all far exceed as stronger "stores of value", both because of their historicity, and also because of their technology, that is a technology that is stable.
Not to mention the complete and utter lack of privacy of Bitcoin because of it's public ledger. Everyone knows everyone else's entire transaction history, and any large enough actor can find that out. Traditional stores of value don't have that problem, or rather not nearly as publicly visible.
Cryptocurrencies, and digital currencies do have place, but I don't think we've come to any sort of equilibrium as to what its role will be in society, which is why I don't think Bitcoin will succeed as "store of value", or currency.