completely unaware that they have a problem until it's too late
They didn't 'have' a problem, they 'were' the problem!
Any instance where a crew member captures an airspeed deviation during approach
You make it sound as though the airspeed 'deviation' (as you call it) was a fault that needed to be noticed & then fixed. Airspeed is a primary flight instrument & you need to be 'flying' airspeed as well as attitude when on approach, or at any other time really. Giving away
total control of airspeed to the machine by not monitoring it, means you are not flying the aircraft. Rather, it is flying you. The consequences of doing that are now splashed all over the world press, with the associated negative impression of our profession by the general public.