The success or otherwise of an ejection is hugely affected by the upward or downward vector of the aircraft as the seat leaves the airframe. I spent all my flying career on ejection seats, both rocket zero/zero seats and non-rocket seats with height and/or speed limits. Hopefully, I was always aware of those limits, particularly in one early jet aircraft where there was a gap between lift off speed and a safe ejection speed/height.
After hanging up my flying gloves, I became a ground school instructor, part of which was teaching ab-initio students about the seat they were going to use. I used a clip from a USAF training film showing the crew leaving an F4 as the aircraft pitched up uncontrollably after liftoff. One occupant went out as the aircraft still had an upward vector, the second went out higher but the aircraft had stopped climbing, the chute of the first ejectee opened at a greater height, despite ejecting at a lower height.