It exists in the US as well (Zelle), except due to the super high number of banks, not all will have feature parity / have it enabled. The major banks like Chase support QR code scanning for instant transfers, smaller ones might require a phone number or email input via keyboard.
It will exist soon in the US since FedPay was rolled out this year. It will take a while for banks to support it, but my guess is everyone will support it as replacement to ACH.
I don't think Venmo will die since there is a need for app to provide nice interface. But Zelle has been lobbying against FedPay since it will destroy them.
In Australia, we have instant transfers between bank accounts.
I imagine the US will get to that point soon in which case there is no benefit to crypto for this use case.