I keep seeing this type of comment in Bitcoin threads. Is this something people in the Bitcoin space widely believe, that bank transfers are necessarily slow and expensive? Free, near-instant bank transfers have been a thing for a few years now (a decade in the UK IIUC).

Or have I completely misunderstood what you were saying?

The throughput in banks is orders of magnitudes greater than for Bitcoin. Transactions are carried out instantly and processed at least once daily in huge and super fast batches.

You could add a layer for fast transactions to BTC but IIRC it can't handle processing nearly enough of them into the blockchain per day.

You really need to change banks if this happens to you. Bank transfers are done in seconds in the SEPA area. Pretty sure there's something similar outside of Europe, too.