In theory, one of the benefits of no race radio is the "out of sight, out of mind" factor. That being, once a rider attacks up the road, in the current system it's well known in the team cars almost exactly where that rider is, and how to calculate the speed needed to catch them before the finish. This is why time and again someone goes on the attack, and the peloton catches them under 2k from the finish. Or if they get away and stay away, it's by a manageable amount.
With no radios, the thinking is that with a rider up the road and out of sight, that the peloton will have to discuss amongst each other when to chase, and how much. And in this situation, it's much more likely someone will be caught 20km from the finish, or win by a couple of minutes.
As to stopping technological advancements because the riders want it, that is a bigger subject that could include fairings, super light bikes, aero equipment. And in the future if we open everything up we could eventually see cross data where teams could know through GPS where every single rider is on the course, plus know their HRM, wattage output, etc. not just their riders but other riders as well. Not the kind of racing I'd like to see.