design time + weight = strength.
The wing needs to pass flex tests from the FIA, but these tests are an application of pressure, not a sudden hit.
The wings do their best work when the car is running level and even, which was why active suspension was so dominating as a tool, and also why the mass damper that Renault used also made such a difference.
This is the video you were likely speaking of:
F1 Super Slo Mo
So, usually when you see the wing shaking so much, the car is bouncing over kerbs, where the balance will be upset regardless if the wing is shaking or not.
Also, the effects of the wings are minimal at the usually slow speeds they are running when bouncing over kerbs.
The effect of the wing remaining completely rigid will no be of great help when the car is bouncing up and down anwyay.
If the wing started to shake and reverberate to a natural frequency at a high speed, then it would be worth pursuing by the teams, as it would likely disintegrate.