Taking radios out of cycling is like putting a football manager in the back fo the stand during matches.
Managers need to communicate with the riders, I agree, I don't like them, the riders don't like them, but without them trying out certain tactics would just not work.
Team cars need to be able to replace flat tyres, you make a rider change his own tyre on the side of the road, he may as well call it a day, unless the whole team work try and work to reduce a 15 minutes deficite, and how do you change a tub at the side of the road?