Was Enigma really that hard to crack, given that you had access to hundreds of messages per network per day?
Yes, it's just that the messages were often low value.

There was nothing like gps back then, you would not get a real time location of a submarine. At best you'd get a lat/long which is precise to several km and then spend hours trying to get a plane there.

You'd get vague obvious warnings like "Germans may be attacking this convoy"- and there was no central directions, it was up to the uboat commander to decide the details .

But that was important enough that the government gave them a few people to help them crack these messages.

So given such a small, resource poor team was allocated to the task it was a big accomplishment.