Earlier quoted context omitted.
This is not a valid way of judging RMS or his claims. He isn't complaining about the concept of a technology that allows people to talk while on the go. Rather, he is complaining about the specific implementation of mobile tech with which we're currently saddled. To answer seriously, however, the largest effect of reduced cell phone use would be that automobiles would be much safer, for their passengers and for every…
Then again, in the case that an auto accident does occur, there might not be someone with a cell phone to immediately call emergency services.
Just to point out a bit of an overly binary comparison: There is a middle ground here — consider a powered-off, pre-paid phone. No constant texting and so on, but also there for emergencies (in which instance, you turn it on exactly when you actually want to be tracked — by emergency personnel).