From a practical perspective...
I recently traded my 13mpx 5d for the 50mpx 5ds. And I can say that even using my non-“L” prime lenses that there is a very clear increase in detail from the 5ds even when hand held.
If you think about it, if using a low mpx camera, adding camera shake will just add more blur to even a low pixel count image. So, in the right circumstances, a tripod is required for all cameras. But, the advantages of the 5ds will still be visible, even hand held.
So, don’t feel that you’ve wasted your money with the 5ds without a tripod for every photograph. But, for maximum detail with any camera, a tripod is always best.
