Before mobile apps, the ATM taught the public to transact with a machine. That history still shapes expectations: the interface should be obvious, the result should be certain, and the institution behind it should be accountable.
What changed
Networks grew. Software became central. Monitoring moved from paper logs to live telemetry. Security expanded from the vault to the communication path. The machine remained, but the system around it became the real product.
What stayed
A person still stands in front of steel and asks for cash. If that moment fails, no amount of digital sophistication elsewhere compensates.