Guess you meant "Why Cryptocurrency needs Blockchain."
Blockchain can actually exist without Cryptocurrency, not sure if Cryptocurrency as we know it can exist without Blockchain.
There's also DAG-based coins though (of debatable merit of course, but that's a different discussion).
And I'm still not sure how one would secure a blockchain without incentivising miners / stakers by means of a native token (or by building on top of an existing cryptocurrency).
Cryptocurrency needs Blockchain
[...]
- For anonymity
Blockchains are transparent by design. Anonymity is achieved by specialized transaction formats,.
[...]
- To avoid double-spending
Blockchains don't prevent double-spending. PoW does. (and arguably other forms of Proof-of-Resource such as PoS)