what do you think about the privacy argument? Using blockchain is private, until you've been figured out. Then your whole usage is public with no way to suppress that?
That's not technically true. There are zero-knowledge proofs that can be used to deidentify assets and transactions. As an example, JPMorgan has developed one type: https://www.coindesk.com/jpmorgan-adds-new-privacy-features-to-its-ethereum-based-quorum-blockchain That's one of the wonders of Ethereum. Because it is turing-complete, it unleashes a huge amount of creativity. Bitcoin has transaction mixers, but they are far from optimal. I am not long-term bullish on bitcoin. BTW, these zero-knowledge proofs have now been leveraged for both privacy and increased bandwidth on the main chain: https://www.theblockcrypto.com/post/80495/aztec-ethereum-layer-2-unveil