But you can usually detect mechanical problems early: for example, wear or cracks in metal parts. Software may work perfectly for ten years, then finally hit the rare bug that causes it to fail for no apparent reason.
It can happen with mechanical stuff too, Air Midwest 5481 back in 2003. Someone introduced a mechanical 'bug' in that they rigged the elevator cables incorrectly. It flew OK for several flights until circumstances conspired to trip the bug, in the form of a CofG too far aft and it pitched up and stalled. OK, not quite ten years, but no one detected the error and had the error not been made, it would have been recoverable - the limited elevator travel due to the error meant it couldn't cope.