Cryptocurrencies would be best categorized as digital assets whose properties, capabilities and value propositions are wildly different depending on what they were created for and sometimes what the market decided later.
That's actually how they're categorized legally wherever they're regulated. They're property. Disposing them is a taxable event unlike disposing money.
The market seems to treat every cryptocurrency as property as well.
The Bitcoin white paper talks about digital cash underpinned by a distributed ledger on a blockchain. It's clear that transferability and the uncensorability thereof is central to the nature of cryptocurrency.
But the value proposition of cryptocurrency as most market participants seem to understand it has to do with the security of the chain. That is very understandable. No one would want to store billions of dollars on an insecure ledger. It's precisely the security that gives Bitcoin value.
The term cryptocurrency seems to be throwing off a lot of no-coiners. I just noticed a conversation today where a bunch of no-coiners were speculating that Elon Musk's tweet was the beginning of the end for Bitcoin and that some other "more efficient" coin was surely going to steal its thunder. I did not bother to set the record straight because that kind of talk is all too common.