What the blockchain’s purpose is not:
Cryptocurrencies are not currencies. Cryptocurrencies on the blockchain are not usable as currencies, as the value fluctuates so heavily and the transaction costs are gargantuan. This is also why the “cryptocurrencies provides banking to the unbanked” argument falls flat.
NFTs don’t create a new art market. Humans have traded art for a very long time. NFTs don’t create a new market for art.
NFTs don’t provide scarcity. Objects that have an NFT are trivially reproduced.
NFTs don’t guarantee persistence. NFTs are stored on the blockchain, but the objects for which NFTs are created are not. Those objects can disappear or be changed at any time.
The blockchain is not decentralised. The blockchain is an append-only ledger and can thus only ever grow in size. The ETH blockchain is roughly 10 TB in size at the time of writing, and is constantly growing. This puts it out of reach for people who can’t afford the hard drive space. This is one of the reasons why centralised services are popping up.
The blockchain is not decentralised. Blockchains are not interoperable.
What the blockchain’s purpose is: