I have prepared an infography to try to demystify the importance of sensor size regarding Dynamic range, vs sensor technology which has a much broader influence.
To do it I have taken the Sony A7R III sensor's dynamic range as a reference, and I have calculated which
crop on this camera would yield the same SNR for a given output size than the rest of most popular FF cameras (DR figures taken from DxOMark).
Not meaning this crop can substitute the cameras under comparison by any means, to begin with the crops have lower pixelcount. It's just a visual way to represent in terms of sensor size (crop) what improved technology can bring to us.
So the interpretation is: a 0,9Mpx crop on the Sony A7R III would produce the same visible noise in the shadows as a complete Canon 6D II capture once both images are scaled to the same output size.
The table includes APS and M4/3 sensors, ranking from higher to lower pixelcount of the crop:
The statistics to do the calculations is the usual quadrature binning assumption: rescaling 4 pixels into 1 doubles SNR, i.e. increases DR by 1 stop. I translated DxOMark's DR differences into linear scaling and hence equivalent crop factors for each compared camera.
Regards!