You're right, about photography. In video, however, you need tons and tons and tons and tons of sensitivity in addition to dynamic range because you can only use fast "shutter" (electronic, not physical, of course) speeds. Needing to create a perfect image 24, 30, or 60 times a second in the dark requires a very different bag of tricks. This is why, for example, having fewer and larger pixels is vastly preferable for motion versus stills.
