> ...why can't the big players (at least) confirm things quickly? Why can't there be an easy status to say if a check has truly "cleared" or not?
Consider a forged check with valid identifying information. Think about what the other side of that transaction looks like. That other customer needs time to review incoming transactions to their account, notice the errant one, and dispute it. And so waiting this time is the only practical way the receiving bank can fully clear a transaction.
The timeframe is much longer - 60 days AFAIK. So essentially you verify every statement, or verify the online transactions every month and a half.
Even with the smaller attack surface of a banking system based on only "pushing" money, surely other countries must have analogous timeframes for reporting unauthorized transactions (eg from an authorized login).
Consider a forged check with valid identifying information. Think about what the other side of that transaction looks like. That other customer needs time to review incoming transactions to their account, notice the errant one, and dispute it. And so waiting this time is the only practical way the receiving bank can fully clear a transaction.