Bearings and shaft
Seems to be a large issue that no one has addressed here. Most of these modern failures have been on engines designed decades ago and modified by adding stages, increasing fan diameter etc then upping the thrust rating. In short, engine manufacturers are not designing as many new engines as they are attempting to squeeze more thrust out of the same old design. The bearings (positioning) and shaft's (spans) take a harmonic beating that emanates into disks, blades and blade contact with the case. Attention to engine cool down periods has been a short response from the manufacturers, shaft warping on hot engines is becoming a large problem.
A 6 foot tall fan blade is one hell of a projectile thus the attention of fan blade containment.