Versions of the Enigma machine had been around for years before the German adopted it. It wasn't some sort of technical marvel it was built using the technology of the day.

The problem with the Enigma, was the culture of the German military and how they utilised it.

To give one example, the volume of signals traffic being transmitted using it was a weakness. There were incidences of ships in port in Germany, sending radio messages instead of using the land based telecom's infrastructure which was easily accessible.

Or more infamously there was the incident on Hitlers birthday when multiple stations sent birthday wishes over the various nets all encrypted. This would have given any reasonably resourced code breakers the opportunity to decode individual signals. It gave the British the means to decode them in almost real time.

The Enigma seemed to give the German military license to abandon good military practice when it came to the use of Signals, their faith in the machine was total.

The Japanese in contrast had much better procedures when it came to using signals. Though in their case they tended to be more concerned about location finding rather than the messages being decrypted.