Being an engineer does not exclusively mean you are focused on efficiency. It means determining the balance of reliability, functionality, efficiency, and a wealth of other factors as applied to the specific use case.
Bitcoin is not made to be efficient, it's made to be a self-sufficient decentralized monetary system. Decentralization isn't efficient compared to centralization, but it offers other benefits that are powerful.
The whole point is not to get rid of banks and replace them with crypto. It's about building a system that's more democratized, robust, and resistant to loss of purchasing power over time. Bitcoin has done that well, and it's the cornerstone of the new decentralized financial infrastructure.
Even if I were optimistic about cryptocurrency, I would be opposed to places like Coinbase. The whole point is supposedly to get rid of banks and replace them with cryptography. Coinbase is building the same old banking system all over again, but with slower databases and regulation set back to the 1930s.