I would argue it is harder and more dangerous. With the phone you need to unlock it, select camera app, then make sure it focuses (which doesn't work that great at night, you have to look at the screen, tap on the area you want to focus), second thing is that due to low light conditions to avoid blurring you need to be perfectly still (which is hard to do in a moving car, especially if you are driving), this makes you check the picture then retry, then check again etc.
You likely could spend even a minute looking at the screen to make sure you got a good picture. Each time you switch your eyes need to adjust their focus which also takes a second, but that it is insignificant to the rest.
BTW: even changing the radio station takes enough attention to cause accidents (that's why they started adding controls on the wheel), but taking a picture (especially at night) is way more dangerous.