An interesting point, not one I have considered, but well worthy of debate.
My own immediate reaction is the camera is itself physically well mounted in a very well motion /vibration damped , thus stabilised location. Afterall we need it to be for our cars to offer any comfort. [ one of mine on my Brompton cycle handlebars could well benefit]
Plus the individual images are captured in milli seconds, so the image in most shots can't move across the frame very much in the time interval.
It's not like its being held, so I would think any digital stabilisation in our use has to yield minimum benefits.