deptrai:
The A380 went through about 2500 hours of flight testing. It wasn't enough to uncover the uncontained engine failure waiting to happen.
There are early failures, and there are late failures.
The A380 (QF R-R Trent 900) problem was an early failure, immature manufacturing quality issue, which revealed an architecture problem in the engine design. Unloaded turbine discs have been failing for many decades!
Late failures are associated with old tired hardware (fatigue), or with second or third party operators who lack the experience of the original owners.