A speculative instrument is the opposite of a store of value.
A 'store of value' is like real estate - low-risk, probably low-return, but you can park your money there and in X years, it's going to mostly be there. US Bonds.
Your bank account, i.e. USD is a decent, though not great 'store of value'. Your USD is not going to go $0 overnight.
Speculative investments are there to generate return almost always involve more risk.
BTC could go to $0 tomorrow. Suppose the US Gov. makes everyone legally declare their BTC assets as assets and they are subject to taxation etc.. That might pull the plug on BTC, but worse, cause a stampede crash in a highly volatile situation. There are many reasons that a rush-to-exit could happen for BTC. So - speculation - not a 'store of value'
These other fetures of BTC may have been important early on but they are not what gives it value.
Because nobody is using BTC as a currency, almost none of those points are pragmatically relevant - yes - in theory, they need to exist to have gotten it off the ground.