Dimitri, I come from the car racing world where radios are everywhere and helpful given the size of the track, the distance from the track of the crew and spotting.
I certainly agree that radios can be distracting and not as useful as one might think because you can’t use them at most kart races.
However, what I like about them is that they can provide immediate feedback for the driver and are great as a coaching tool. When I can tell my driver at the point on the track I need to coach that he needs to come wider, go in deeper and then tell him when he’s out of the corner whether it was good or not – I think its worth it. To me it accelerates the learning and also reduced “wasted” laps on the track.
The trick though is that if you use it too much – they can become dependent on it. So its a balance. Each kid is different and you have to judge for each of them individually in my opinion.
Oh, I also only have a radio that my driver can listen but can’t talk back (that’s good for more than one reason LOL).