We cracked down on driving under the influence with changes from DWI to DUI. In the 10-15 years you mention, the prevalence of distracted driving from mobile devices has gotten out of hand. There's no field sobriety test that can prove one was distracted by a device. That makes this much more difficult to crack down on.
Sure, though it is very easy to visually identify drivers looking at their phones. (Unless they have illegal tint.)